4 resultados para teams and networking
em Duke University
Resumo:
ABSTRACT
This thesis examines the theological correlation between the role of the church, the identity and role of the African American male, and the effectiveness of fatherhood. The study begins with an in-depth analysis of how absentee fathers cause a crisis in the family. The absence of fathers from the home causes children to suffer financially, socially and psychologically, and therefore causes a disruption in the community as a whole. Focus on the Family founder and leader, Dr. James Dobson, confirms that “our very survival as a people will depend upon the presence or absence of masculine leadership in millions of homes.” In person interviews of African American Christian males and interpretation of the scriptures are just two of the methods used in this study to explore the theological norm of fatherhood. Collectively, the case studies and statistical data within this study explore attempts to remedy the crisis through governmental policies and networking within the community. The final chapter examines the role of urban churches and clergy in teaching effective fatherhood practices. Within the conclusion, it is made clear that the church is responsible for establishing the theological framework and principles for understanding the intended role of being a father. Another conclusion of this study is the acknowledgement of the African American community’s role in shaping and reforming the identity and role of the African American male as a father in the home. The African American community and the church must continue working in tandem to encourage organic social networks that will promote a model for effective fatherhood practices.
Resumo:
To provide biological insights into transcriptional regulation, a couple of groups have recently presented models relating the promoter DNA-bound transcription factors (TFs) to downstream gene’s mean transcript level or transcript production rates over time. However, transcript production is dynamic in response to changes of TF concentrations over time. Also, TFs are not the only factors binding to promoters; other DNA binding factors (DBFs) bind as well, especially nucleosomes, resulting in competition between DBFs for binding at same genomic location. Additionally, not only TFs, but also some other elements regulate transcription. Within core promoter, various regulatory elements influence RNAPII recruitment, PIC formation, RNAPII searching for TSS, and RNAPII initiating transcription. Moreover, it is proposed that downstream from TSS, nucleosomes resist RNAPII elongation.
Here, we provide a machine learning framework to predict transcript production rates from DNA sequences. We applied this framework in the S. cerevisiae yeast for two scenarios: a) to predict the dynamic transcript production rate during the cell cycle for native promoters; b) to predict the mean transcript production rate over time for synthetic promoters. As far as we know, our framework is the first successful attempt to have a model that can predict dynamic transcript production rates from DNA sequences only: with cell cycle data set, we got Pearson correlation coefficient Cp = 0.751 and coefficient of determination r2 = 0.564 on test set for predicting dynamic transcript production rate over time. Also, for DREAM6 Gene Promoter Expression Prediction challenge, our fitted model outperformed all participant teams, best of all teams, and a model combining best team’s k-mer based sequence features and another paper’s biologically mechanistic features, in terms of all scoring metrics.
Moreover, our framework shows its capability of identifying generalizable fea- tures by interpreting the highly predictive models, and thereby provide support for associated hypothesized mechanisms about transcriptional regulation. With the learned sparse linear models, we got results supporting the following biological insights: a) TFs govern the probability of RNAPII recruitment and initiation possibly through interactions with PIC components and transcription cofactors; b) the core promoter amplifies the transcript production probably by influencing PIC formation, RNAPII recruitment, DNA melting, RNAPII searching for and selecting TSS, releasing RNAPII from general transcription factors, and thereby initiation; c) there is strong transcriptional synergy between TFs and core promoter elements; d) the regulatory elements within core promoter region are more than TATA box and nucleosome free region, suggesting the existence of still unidentified TAF-dependent and cofactor-dependent core promoter elements in yeast S. cerevisiae; e) nucleosome occupancy is helpful for representing +1 and -1 nucleosomes’ regulatory roles on transcription.
Resumo:
Allocating resources optimally is a nontrivial task, especially when multiple
self-interested agents with conflicting goals are involved. This dissertation
uses techniques from game theory to study two classes of such problems:
allocating resources to catch agents that attempt to evade them, and allocating
payments to agents in a team in order to stabilize it. Besides discussing what
allocations are optimal from various game-theoretic perspectives, we also study
how to efficiently compute them, and if no such algorithms are found, what
computational hardness results can be proved.
The first class of problems is inspired by real-world applications such as the
TOEFL iBT test, course final exams, driver's license tests, and airport security
patrols. We call them test games and security games. This dissertation first
studies test games separately, and then proposes a framework of Catcher-Evader
games (CE games) that generalizes both test games and security games. We show
that the optimal test strategy can be efficiently computed for scored test
games, but it is hard to compute for many binary test games. Optimal Stackelberg
strategies are hard to compute for CE games, but we give an empirically
efficient algorithm for computing their Nash equilibria. We also prove that the
Nash equilibria of a CE game are interchangeable.
The second class of problems involves how to split a reward that is collectively
obtained by a team. For example, how should a startup distribute its shares, and
what salary should an enterprise pay to its employees. Several stability-based
solution concepts in cooperative game theory, such as the core, the least core,
and the nucleolus, are well suited to this purpose when the goal is to avoid
coalitions of agents breaking off. We show that some of these solution concepts
can be justified as the most stable payments under noise. Moreover, by adjusting
the noise models (to be arguably more realistic), we obtain new solution
concepts including the partial nucleolus, the multiplicative least core, and the
multiplicative nucleolus. We then study the computational complexity of those
solution concepts under the constraint of superadditivity. Our result is based
on what we call Small-Issues-Large-Team games and it applies to popular
representation schemes such as MC-nets.