106 research outputs found
Managing A Paradox–Design Principles for Executives’ IT Support
How are companies managed today and what part does state-of-the-art IT play? Executive information systems (EIS) should support top managers in managing their companies. But many executives complain that EIS bear little relevance to their management task (functional requirements) and fail even more to accommodate their working style (design requirements). This article focuses on the latter and contributes to new-generation EIS by identifying twelve principles for their design. The first step in doing so is to systematically develop requirements criteria for EIS design. On this point, our research revealed a twofold gap: as the rigor of scientific models (e.g. structural models of IS user satisfaction and technology acceptance) increases, they become less relevant for direct use in practice. At the same time, practitioner journals demonstrate relevance, but do not evidence strong rigor. Linking the requirements criteria with rigor and relevance, this article applies the principle of economic efficiency. In a second step, using that schema, design principles for new-generation EIS are derived. They are based on gaps identified in an empirical study and the findings of four instantiations within the chemicals, logistics, high-tech, and automotive supplier industries
A Maturity Model for Management Control Systems: Five Evolutionary Steps to Guide Development
Corporate management in today's international companies has become increasingly complex. To cope with the growing challenges, information technology (IT)-based management control systems (MCSs) covering reporting, planning, and consolidation have been deployed. Despite their tradition in management research, the ‘right' setup of MCSs is still challenging. Maturity models (MMs) are an established instrument to identify strengths and weaknesses of certain domains. As existing MMs rather focus on single MCS domains, neglect an IT perspective and miss a sound methodical foundation, this paper outlines an empirically and algorithmically constructed MCS MM. The model consists of three partial MMs for reporting, planning, and consolidation, which are integrated into one holistic MCS MM. The five levels of the MCS MM guide MCS evolution from a basic, mandatory/external-driven MCS (level1) to a balanced MCS (level2), and a comprehensive MCS (level3). Ultimately, MCSs show a strong strategic focus (level4) and leverage the potentials of modern IT (level5
A Maturity Model for Management Control Systems - Five Evolutionary Steps to Guide Development
Corporate management in today’s international companies has become increasingly complex. To cope with the growing challenges, information technology (IT)-based management control systems (MCSs) covering reporting, planning, and consolidation have been deployed. Despite their tradition in management research, the ‘right’ setup of MCSs is still challenging. Maturity models (MMs) are an established instrument to identify strengths and weaknesses of certain domains. As existing MMs rather focus on single MCS domains, neglect an IT perspective and miss a sound methodical foundation, this paper outlines an empirically and algorithmically constructed MCS MM. The model consists of three partial MMs for reporting, planning, and consolidation, which are integrated into one holistic MCS MM. The five levels of the MCS MM guide MCS evolution from a basic, mandatory/external-driven MCS (level 1) to a balanced MCS (level 2), and a comprehensive MCS (level 3). Ultimately, MCSs show a strong strategic focus (level 4) and leverage the potentials of modern IT (level 5)
Quantitative Analysis of Protein Dynamics during Asymmetric Cell Division
SummaryIn dividing Drosophila sensory organ precursor (SOP) cells, the fate determinant Numb and its associated adaptor protein Pon localize asymmetrically and segregate into the anterior daughter cell, where Numb influences cell fate by repressing Notch signaling. Asymmetric localization of both proteins requires the protein kinase aPKC and its substrate Lethal (2) giant larvae (Lgl) [1–3]. Because both Numb and Pon localization require actin and myosin [4–6], lateral transport along the cell cortex has been proposed as a possible mechanism for their asymmetric distribution [5]. Here, we use quantitative live analysis of GFP-Pon and Numb-GFP fluorescence and fluorescence recovery after photobleaching (FRAP) to characterize the dynamics of Numb and Pon localization during SOP division. We demonstrate that Numb and Pon rapidly exchange between a cytoplasmic pool and the cell cortex and that preferential recruitment from the cytoplasm is responsible for their asymmetric distribution during mitosis. Expression of a constitutively active form of aPKC impairs membrane recruitment of GFP-Pon. This defect can be rescued by coexpression of nonphosphorylatable Lgl, indicating that Lgl is the main target of aPKC. We propose that a high-affinity binding site is asymmetrically distributed by aPKC and Lgl and is responsible for asymmetric localization of cell-fate determinants during mitosis
Towards in-situ diagnostics of multi-photon 3D laser printing using optical coherence tomography
3D printing of inherently nanoporous polymers via polymerization-induced phase separation
3D printing offers enormous flexibility in fabrication of polymer objects with complex geometries. However, it is not suitable for fabricating large polymer structures with geometrical features at the sub-micrometer scale. Porous structure at the sub-micrometer scale can render macroscopic objects with unique properties, including similarities with biological interfaces, permeability and extremely large surface area, imperative inter alia for adsorption, separation, sensing or biomedical applications. Here, we introduce a method combining advantages of 3D printing via digital light processing and polymerization-induced phase separation, which enables formation of 3D polymer structures of digitally defined macroscopic geometry with controllable inherent porosity at the sub-micrometer scale. We demonstrate the possibility to create 3D polymer structures of highly complex geometries and spatially controlled pore sizes from 10 nm to 1000 µm. Produced hierarchical polymers combining nanoporosity with micrometer-sized pores demonstrate improved adsorption performance due to better pore accessibility and favored cell adhesion and growth for 3D cell culture due to surface porosity. This method extends the scope of applications of 3D printing to hierarchical inherently porous 3D objects combining structural features ranging from 10 nm up to cm, making them available for a wide variety of applications
Imaging features of fibrolamellar hepatocellular carcinoma in gadoxetic acid-enhanced MRI
Background: Fibrolamellar hepatocellular carcinoma (FLC) is a rare malignancy occurring in young patients without cirrhosis. Objectives of our study were to analyze contrast material uptake in hepatobiliary phase imaging (HBP) in gadoxetic acid-enhanced liver MRI in patients with FLC and to characterize imaging features in sequence techniques other than HBP.
Methods: In this retrospective study on histology-proven FLC, contrast material uptake in HBP was quantitatively assessed by calculating the corrected FLC enhancement index (CEI) using mean signal intensities of FLC and lumbar muscle on pre-contrast imaging and HBP, respectively. Moreover, enhancement patterns in dynamic contrast-enhanced MRI and relative signal intensities compared with background liver parenchyma were determined by two radiologists in consensus for HBP, diffusion-weighted imaging using high b-values (DWI), and T2 and T1 weighted pre-contrast imaging.
Results: In 6 of 13 patients with FLC gadoxetic acid-enhanced liver MRI was available. The CEI suggested presence of HBP contrast material uptake in all FLCs. A mean CEI of 1.35 indicated FLC signal increase of 35% in HBP compared with pre-contrast imaging. All FLCs were hypointense in HBP compared with background liver parenchyma. Three of 6 FLCs had arterial hyperenhancement and venous wash-out. In DWI and T2 weighted imaging, 5 of 6 FLCs were hyperintense. In T1 weighted imaging, 5 of 6 FLCs were hypointense.
Conclusion: Hepatobiliary uptake of gadoxetic acid was quantitatively measurable in all FLCs investigated in our study. The observation of hypointensity of FLCs in HBP compared with background liver parenchyma emphasizes the role of gadoxetic acid-enhanced liver MRI for non-invasive diagnosis of FLC and its importance in the diagnostic work-up of indeterminate liver lesions
Update of Guidelines for laparoscopic treatment of ventral and incisional abdominal wall hernias (International Endohernia Society (IEHS)) : Part B
In 2014 the International Endohernia Society (IEHS) published the first international "Guidelines for laparoscopic treatment of ventral and incisional abdominal wall hernias". Guidelines reflect the currently best available evidence in diagnostics and therapy and give recommendations to help surgeons to standardize their techniques and to improve their results. However, science is a dynamic field which is continuously developing. Therefore, guidelines require regular updates to keep pace with the evolving literature. Methods For the development of the original guidelines all relevant literature published up to year 2012 was analyzed using the ranking of the Oxford Centre for Evidence-Based-Medicine. For the present update all of the previous authors were asked to evaluate the literature published during the recent years from 2012 to 2017 and revise their statements and recommendations given in the initial guidelines accordingly. In two Consensus Conferences (October 2017 Beijing, March 2018 Cologne) the updates were presented, discussed, and confirmed. To avoid redundancy, only new statements or recommendations are included in this paper. Therefore, for full understanding both of the guidelines, the original and the current, must be read. In addition, the new developments in repair of abdominal wall hernias like surgical techniques within the abdominal wall, release operations (transversus muscle release, component separation), Botox application, and robot-assisted repair methods were included. Results Due to an increase of the number of patients and further development of surgical techniques, repair of primary and secondary abdominal wall hernias attracts increasing interests of many surgeons. Whereas up to three decades ago hernia-related publications did not exceed 20 per year, currently this number is about 10-fold higher. Recent years are characterized by the advent of new techniques-minimal invasive techniques using robotics and laparoscopy, totally extraperitoneal repairs, novel myofascial release techniques for optimal closure of large defects, and Botox for relaxing the abdominal wall. Furthermore, a concomitant rectus diastasis was recognized as a significant risk factor for recurrence. Despite still insufficient evidence with respect to these new techniques it seemed to us necessary to include them in the update to stimulate surgeons to do research in these fields. Conclusion Guidelines are recommendations based on best available evidence intended to help the surgeon to improve the quality of his daily work. However, science is a continuously evolving process, and as such guidelines should be updated about every 3 years. For a comprehensive reference, however, it is suggested to read both the initially guidelines published in 2014 together with the update. Moreover, the presented update includes also techniques which were not known 3 years before
Is MRCP necessary to diagnose pancreas divisum?
Background: The purpose of this study is to compare the performance of three-dimensional magnetic resonance cholangiopancreatography (3D-MRCP) with non-MRCP T2-weighted magnetic resonance imaging (MRI) sequences for diagnosis of pancreas divisum (PD).
Methods: This is a retrospective study of 342 consecutive patients with abdominal MRI including 3D-MRCP. 3D-MRCP was a coronal respiration-navigated T2-weighted sequence with 1.5 mm slice thickness. Non-MRCP T2-weighted sequences were (1) a coronal inversion recovery sequence (TIRM) with 6 mm slice thickness and (2) a transverse single shot turbo spin echo sequence (HASTE) with 4 mm slice thickness. For 3D-MRCP, TIRM, and HASTE, presence of PD and assessment of evaluability were determined in a randomized manner. A consensus read by two radiologists using 3D-MRCP, non-MRCP T2-weighted sequences, and other available imaging sequences served as reference standard for diagnosis of PD. Statistical analysis included performance analysis of 3D-MRCP, TIRM, and HASTE and testing for noninferiority of non-MRCP T2-weighted sequences compared with 3D-MRCP.
Results: Thirty-three of 342 patients (9.7%) were diagnosed with PD using the reference standard. Sensitivity/specificity of 3D-MRCP for detecting PD were 81.2%/69.7% (p < 0.001). Sensitivity/specificity of TIRM and HASTE were 92.5%/93.9 and 98.1%/97.0%, respectively (p < 0.001 each). Grouped sensitivity/specificity of non-MRCP T2-weighted sequences were 99.8%/91.0%. Non-MRCP T2-weighted sequences were non-inferior to 3D-MRCP alone for diagnosis of PD. 20.2, 7.3%, and 2.3% of 3D-MRCP, TIRM, and HASTE, respectively, were not evaluable due to motion artifacts or insufficient duct depiction.
Conclusions: Non-MRCP T2-weighted MRI sequences offer high performance for diagnosis of PD and are noninferior to 3D-MRCP alone.
Trial registration Not applicable
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