Further clinical and molecular delineation of the 15q24 microdeletion syndrome

Background Chromosome 15q24 microdeletion syndrome is a rare genomic disorder characterised by intellectual disability, growth retardation, unusual facial morphology and other anomalies. To date, 20 patients have been reported; 18 have had detailed breakpoint analysis. Aim To further delineate the features of the 15q24 microdeletion syndrome, the clinical and molecular characterisation of fifteen patients with deletions in the 15q24 region was performed, nearly doubling the number of reported patients. Methods Breakpoints were characterised using a custom, high-density array comparative hybridisation platform, and detailed phenotype information was collected for each patient. Results Nine distinct deletions with different breakpoints ranging in size from 266 kb to 3.75 Mb were identified. The majority of breakpoints lie within segmental duplication (SD) blocks. Low sequence identity and large intervals of unique sequence between SD blocks likely contribute to the rarity of 15q24 deletions, which occur 8-10 times less frequently than 1q21 or 15q13 microdeletions in our series. Two small, atypical deletions were identified within the region that help delineate the critical region for the core phenotype in the 15q24 microdeletion syndrome. Conclusion The molecular characterisation of these patients suggests that the core cognitive features of the 15q24 microdeletion syndrome, including developmental delays and severe speech problems, are largely due to deletion of genes in a 1.1-Mb critical region. However, genes just distal to the critical region also play an important role in cognition and in the development of characteristic facial features associated with 15q24 deletions. Clearly, deletions in the 15q24 region are variable in size and extent. Knowledge of the breakpoints and size of deletion combined with the natural history and medical problems of our patients provide insights that will inform management guidelines. Based on common phenotypic features, all patients with 15q24 microdeletions should receive a thorough neurodevelopmental evaluation, physical, occupational and speech therapies, and regular audiologic and ophthalmologic screenin

Zur Methodologie der technologischen Forschung in der Betriebswirtschaftslehre

In den letzten Jahren ist wieder der Ruf nach mehr Praxisrelevanz der Betriebswirtschafts- bzw. Managementlehre laut geworden. Unter relevanter Forschung wird dabei in der Regel eine Forschung verstanden, die letztlich zu instrumentellem Wissen führt, das in der Unternehmenspraxis einsetzbar ist. Eine solche, auf Entwicklung instrumentellen Wissens ausgerichtete Forschung wird auch als technologische Forschung bezeichnet – im Gegensatz zur theoretischen Forschung. Während es in der theoretischen Forschung um „Aufklärung“ geht, d.h. um Erklärung von Zusammenhängen, geht es bei der technologischen Forschung um „Steuerung“ bzw. „Gestaltung“. Theoretische Aussagen sind Aussagen über Ursache-Wirkungs-Beziehungen, technologische Aussagen betreffen dagegen Mittel-Zweck-Beziehungen. In diesem Beitrag wollen wir darlegen, dass theoretische und technologische Aussagenzusammenhänge zwei eigenständige Forschungszweige darstellen und damit die Notwendigkeit erwächst, eine eigene Methodologie technologischer Aussagenzusammenhänge zu entwerfen. Es sollen Ansatzpunkte aufgezeigt werden, wie eine solche Methodologie technologischer Aussagenzusammenhänge aussehen kann. Dabei wird auch der Frage nach der Wissenschaftlichkeit technologischer Forschung nachzugehen sein

Precise detection of circular dichroism in a cluster of nano-helices by photoacoustic measurements

Compact samples of nano-helices built by means of a focused ion beam technology with large bandwidth and high dichroism for circular polarization are promising for the construction of built-in-chip sensors, where the ideal transducer must be sufficiently confined without compromising its filtering ability. Direct all-optical measurements revealed the sample’s dichroic character with insufficient details because of scattering and diffraction interference. On the other hand, photoacoustic measurements resulted to be a possible alternative investigation, since they directly deal with absorbed power and allow to get clear evidences of the differential selection for the two opposite polarization states. Multilevel numerical simulations confirmed the experimental results, proving once again the reliability of photoacoustic technique and the versatility of this class of dichroic artificial materials