The Modeling of Anisotropic Fuselage Lining Material

In this paper a theoretical model that can account for the effect of lining anisotropy on sound transmission through fuselage structures is developed. The model allows for anisotropic flow resistivity, tortuosity and elastic moduli. Implicit to the theory is a characteristic dispersion relation of sixth order that yields the allowed wave numbers for wave propagation in anisotropic elastic porous media. In addition, explicit expressions for field variables such as displacements and stresses appropriate for anisotropic foams are derived. Predictions of random incidence sound transmission loss for double panels with anisotropic linings have been performed. To verify the prediction, the theoretical results have been compared with random incidence transmission loss measurements

The Servant Leadership Survey: Development and Validation of a Multidimensional Measure

Purpose: The purpose of this paper is to describe the development and validation of a multi-dimensional instrument to measure servant leadership. Design/Methodology/Approach Based on an extensive literature review and expert judgment, 99 items were formulated. In three steps, using eight samples totaling 1571 persons from The Netherlands and the UK with a diverse occupational background, a combined exploratory and confirmatory factor analysis approach was used. This was followed by an analysis of the criterion-related validity. Findings: The final result is an eight-dimensional measure of 30 items: the eight dimensions being: standing back, forgiveness, courage, empowerment, accountability, authenticity, humility, and stewardship. The internal consistency of the subscales is good. The results show that the Servant Leadership Survey (SLS) has convergent validity with other leadership measures, and also adds unique elements to the leadership field. Evidence for criterion-related validity came from studies relating the eight dimensions to well-being and performance. Implications: With this survey, a valid and reliable instrument to measure the essential elements of servant leadership has been introduced. Originality/Value The SLS is the first measure where the underlying factor structure was developed and confirmed across several field studies in two countries. It can be used in future studies to test the underlying premises of servant leadership theory. The SLS provides a clear picture of the key servant leadership qualities and shows where improvements can be made on the individual and organizational level; as such, it may also offer a valuable starting point for training and leadership development

Intronic splicing enhancers, cognate splicing factors and context-dependent regulation rules

SummaryMost human genes produce multiple splicing isoforms with distinct functions. To systematically understand splicing regulation, we conducted an unbiased screen and identified >100 intronic splicing enhancers (ISEs) that were clustered by sequence similarity into six groups. All ISEs functioned in another cell type and heterologous introns, and their distribution and conservation patterns in different pre-mRNA regions are similar to exonic splicing silencers. Consistently all ISEs inhibited use of splice sites from exonic locations. The putative trans-factors of each ISE group were identified and validated. Five distinct ISE motifs were recognized by hnRNP H and F whose C-terminal domains were sufficient to render context-dependent activities of ISEs. The sixth group was controlled by factors that either activate or suppress splicing. This work provided a comprehensive picture of general ISE activities and provided new models of how a single element can function oppositely depending on its locations and binding factors

The mystery of the cerebellum: clues from experimental and clinical observations

Abstract The cerebellum has a striking homogeneous cytoarchitecture and participates in both motor and non-motor domains. Indeed, a wealth of evidence from neuroanatomical, electrophysiological, neuroimaging and clinical studies has substantially modified our traditional view on the cerebellum as a sole calibrator of sensorimotor functions. Despite the major advances of the last four decades of cerebellar research, outstanding questions remain regarding the mechanisms and functions of the cerebellar circuitry. We discuss major clues from both experimental and clinical studies, with a focus on rodent models in fear behaviour, on the role of the cerebellum in motor control, on cerebellar contributions to timing and our appraisal of the pathogenesis of cerebellar tremor. The cerebellum occupies a central position to optimize behaviour, motor control, timing procedures and to prevent body oscillations. More than ever, the cerebellum is now considered as a major actor on the scene of disorders affecting the CNS, extending from motor disorders to cognitive and affective disorders. However, the respective roles of the mossy fibres, the climbing fibres, cerebellar cortex and cerebellar nuclei remains unknown or partially known at best in most cases. Research is now moving towards a better definition of the roles of cerebellar modules and microzones. This will impact on the management of cerebellar disorders

Engineering splicing factors with designed specificities

Alternative splicing is generally regulated by trans-acting factors that specifically bind pre-mRNA to activate or inhibit the splicing reaction. This regulation is critical for normal gene expression, and dysregulation of splicing is closely associated with human diseases. Here we engineer artificial splicing factors by combining sequence-specific RNA-binding domains of human Pumilio1 with functional domains that regulate splicing. We applied these factors to modulate different types of alternative splicing in selected targets, examine the activity of effector domains from natural splicing factors, and modulate splicing of an endogenous gene, Bcl-x, an anti-cancer target. The designer factor targeted to Bcl-x increased the pro-apoptotic Bcl-xS splicing isoform, thus promoting apoptosis and increasing chemosensitivity of cancer cells to common anti-tumor drugs. Our approach permits the creation of artificial factors to target virtually any pre-mRNA, providing a new strategy to study splicing regulation and manipulate disease-associated splicing events