Gain of 20q11.21 in human pluripotent stem cells impairs TGF-β-dependent neuroectodermal commitment

Gain of 20q11.21 is one of the most common recurrent genomic aberrations in human pluripotent stem cells. Although it is known that overexpression of the antiapoptotic gene Bcl-xL confers a survival advantage to the abnormal cells, their differentiation capacity has not been fully investigated. RNA sequencing of mutant and control hESC lines, and a line transgenically overexpressing Bcl-xL, shows that overexpression of Bcl-xL is sufficient to cause most transcriptional changes induced by the gain of 20q11.21. Moreover, the differentially expressed genes in mutant and Bcl-xL overexpressing lines are enriched for genes involved in TGF-beta- and SMAD-mediated signaling, and neuron differentiation. Finally, we show that this altered signaling has a dramatic negative effect on neuroectodermal differentiation, while the cells maintain their ability to differentiate to mesendoderm derivatives. These findings stress the importance of thorough genetic testing of the lines before their use in research or the clinic

The Impact of Leadership Styles on Employees Productivity in Organizations: A Comparative Study Among Leadership Styles

Successful leaders are facilitators who specifically target skilled and committed workers. Studies in organizational psychology and the research on an organizations actions suggest that management styles and staff motivation are key factors of business performance or failure. This study aimed to study the influence of leadership on the performance of employers in the education ministry and higher education of Somaliland and to define four types, namely, autocratic, transformational, democratic and transactional leadership. This study analyzed the effects of leadership styles on employee efficiency. The final findings have shown that the autocratic leadership model has a detrimental effect on the departments efficiency, which is reflected in high absenteeism, poor morale, decline of job satisfaction, and rotation. The application of egalitarian, transformative and transactional leaders have a positive and important effect on the success of workers assessed by the high morale, efficiency, engagement, and dedication of the employees. The analysis aimed to explore the impact of leadership styles on employee achievement in the Somaliland Ministry of Education and Superior Studies and to define four major styles: autocratic, transformative, democratic and transactional management styles. Consequently, it is possible to assume that democratic, transactional and disruptive leadership has a positive connection to employee performance. In contrast, autocratic models often have a negative relation to employee results. It should also follow and further enhance its powerful aspects of practicing those features of democratic leadership that contribute positively to the companys success

Scheduling internal audit activities:A stochastic combinatorial optimization problem

The problem of finding the optimal timing of audit activities within an organisation has been addressed by many researchers. We propose a stochastic programming formulation with Mixed Integer Linear Programming (MILP) and Constraint Programming (CP) certainty-equivalent models. In experiments neither approach dominates the other. However, the CP approach is orders of magnitude faster for large audit times, and almost as fast as the MILP approach for small audit times. This work generalises a previous approach by relaxing the assumption of instantaneous audits, and by prohibiting concurrent auditin

Using Inference to Reduce Arc Consistency Computation

Constraint satisfaction problems are widely used in artificial intelligence. They involve finding values for problem variables subject to constraints that specify which combinations of values are consistent. Knowledge about properties of the constraints can permit inferences that reduce the cost of consistency checking. In particular, such inferences can be used to reduce the number of constraint checks required in establishing arc consistency, a fundamental constraint-based reasoning technique. A general AC-Inference schema is presented and various forms of inference discussed. A specific algorithm, AC-7, is presented, which takes advantage of a simple property common to all binary constraints to eliminate constraint checks that other arc consistency algorithms perform. The effectiveness of this approach is demonstrated analytically, and experimentally on real-world problems

Constraint-level advice for shaving

International audienceThis work concentrates on improving the robustness of con- straint solvers by increasing the propagation strength of constraint mod- els in a declarative and automatic manner. Our objective is to efficiently identify and remove shavable values during search. A value is shavable if as soon as it is assigned to its associated variable an inconsistency can be detected, making it possible to refute it. We extend previous work on shaving by using different techniques to decide if a given value is an interesting candidate for the shaving process. More precisely, we exploit the semantics of (global) constraints to suggest values, and reuse both the successes and failures of shaving later in search to tune shaving fur- ther. We illustrate our approach with two important global constraints, namely alldifferent and sum, and present the results of an experimen- tation obtained for three problem classes. The experimental results are quite encouraging: we are able to significantly reduce the number of search nodes (even by more than two orders of magnitude), and improve the average execution time by one order of magnitude

POOC - a Platform for Object-Oriented Constraint Programming

In this paper, we describe an implementation-independent object-oriented interface for commercial and academic Constraint Solvers