5,650 research outputs found
Design of RNAi reagents for invertebrate model organisms and human disease vectors
RNAi has become an important tool to silence gene expression in a variety of organisms, in particular when classical genetic methods are missing. However, application of this method in functional studies has raised new challenges in the design of RNAi reagents in order to minimize false positive and false negative results. Since the performance of reagents can be rarely validated on a genome-wide scale, improved computational methods are required that consider experimentally derived design parameters. Here, we describe computational methods for the design of RNAi reagents for invertebrate model organisms and human disease vectors, such as Anopheles. We describe procedures on how to design short and long double-stranded RNAs for single genes, and evaluate their predicted specificity and efficiency. Using a bioinformatics pipeline we also describe how to design a genome-wide RNAi library for Anopheles gambiae
Optimal Strategy Synthesis for Request-Response Games
We show the existence and effective computability of optimal winning
strategies for request-response games in case the quality of a play is measured
by the limit superior of the mean accumulated waiting times between requests
and their responses.Comment: The present paper is a revised version with simplified proofs of
results announced in the conference paper of the same name presented at ATVA
2008, which in turn extended results of the third author's dissertatio
Monodromy Substitutions and Rational Blowdowns
We introduce several new families of relations in the mapping class groups of
planar surfaces, each equating two products of right-handed Dehn twists. The
interest of these relations lies in their geometric interpretation in terms of
rational blowdowns of 4-manifolds, specifically via monodromy substitution in
Lefschetz fibrations. The simplest example is the lantern relation, already
shown by the first author and Gurtas to correspond to rational blowdown along a
-4 sphere; here we give relations that extend that result to realize the
"generalized" rational blowdowns of Fintushel-Stern and Park by monodromy
subsitution, as well as several of the families of rational blowdowns
discovered by Stipsicz-Szab\'o-Wahl.Comment: 28 pages, many figures. v2: minor edits; this version accepted for
publication in Journal of Topolog
River Run Off Measurement With SAR Along Track Interferometry
The paper summarizes the need for global space borne river run-off measurements. It reports about an airborne SAR experiment aimed to measure the surface velocity of the river Isar in Bavaria / Germany. The results from two different SAR techniques, including Along Track Interferometry (ATI) show good correspondence. Finally suggestions for further studies are given
Developmental Processes Critical to the Formation of Servant Leaders in China
Problem. This study concerns three matters: the leader formation process in general, servant leadership formation in particular, and the application to crossing cultures, with China as the primary context. The central problem of this study revolves around leader formation . What events, experiences, people and other formative processes contributed as critical to the formation of exemplary Christian leaders in China?
Method. The design of this research was a narrative, qualitative study that explored the central phenomenon of leader formation. The researcher was the instrument to collect data through in-depth interviews. This study purposefully selected three exemplary Christian Chinese leaders. The participants were asked to share their life stories by recounting the significant formative processes. This questioning was done inductively by asking broad, general questions, without bringing preconceived notions to bear. Participant selection included people of different ages in order to describe from multiple perspectives what was formative in the past as well as the present. The differences between the participants provided sufficient coverage so that their combined stories elicited common themes.
Results . J. Robert Clinton\u27s Leadership Emergence Theory was the theoretical framework for assessing leader formation. The research concluded that leader formation among Chinese Christian leaders occurred mostly through nonformal or informal education, with mentoring and modeling playing a significant role. Of the several process items considered, suffering (internal and external) came across as the most significant life-shaping experience. Formation of being overshadowed formation of knowing and doing. China is changing dramatically, and future leader formation must prepare people to grow holistically while serving the complex challenges of society.
Conclusions. The exemplary Chinese leader embodies honorable qualities and has undergone challenging developmental processes. Chinese culture and worldview have shaped this person\u27s life, as in every culture. However, the exemplary Christian Chinese leader has been subject to formative processes that are sometimes unique and often distinct from what is considered normative leadership development elsewhere. Suggestions toward a universal leadership model were presented. Leader formation globally can learn much from understanding the qualities and developmental processes critical to the formation of the exemplary Chinese leader
Size-Change Termination as a Contract
Termination is an important but undecidable program property, which has led
to a large body of work on static methods for conservatively predicting or
enforcing termination. One such method is the size-change termination approach
of Lee, Jones, and Ben-Amram, which operates in two phases: (1) abstract
programs into "size-change graphs," and (2) check these graphs for the
size-change property: the existence of paths that lead to infinite decreasing
sequences.
We transpose these two phases with an operational semantics that accounts for
the run-time enforcement of the size-change property, postponing (or entirely
avoiding) program abstraction. This choice has two key consequences: (1)
size-change termination can be checked at run-time and (2) termination can be
rephrased as a safety property analyzed using existing methods for systematic
abstraction.
We formulate run-time size-change checks as contracts in the style of Findler
and Felleisen. The result compliments existing contracts that enforce partial
correctness specifications to obtain contracts for total correctness. Our
approach combines the robustness of the size-change principle for termination
with the precise information available at run-time. It has tunable overhead and
can check for nontermination without the conservativeness necessary in static
checking. To obtain a sound and computable termination analysis, we apply
existing abstract interpretation techniques directly to the operational
semantics, avoiding the need for custom abstractions for termination. The
resulting analyzer is competitive with with existing, purpose-built analyzers
Economics and politics of international investment agreements
We analyze the optimal design and implications of international investment agreements. These are ubiquitous, potent and heavily criticized state-to-state treaties that compensate foreign investors against host country policies. Optimal agreements cause national but not global underregulation (""regulatory chill""). The incentives to form agreements and their distributional consequences depend on countries’ unilateral commitment possibilities and the direction of investment flows. Foreign investors benefit from agreements between developed countries at the expense of the rest of society, but not in the case of agreements between developed and developing countries
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