Country clustering in comparative political economy

"In the comparative political economy of rich democracies there is a long tradition of classifying countries into one of a small number of categories based on their economic institutions and policies. The most recent of these is the Varieties of Capitalism project, which posits two major clusters of nations: coordinated and liberal market economies. This classification has generated controversy. We leverage recent advances in mixture model-based clustering to see what the data say on the matter. We find that there is considerable uncertainty around the number of clusters and, barring a few cases, which country should be placed in which cluster. Moreover, when viewed over time, both the number of clusters and country membership change considerably. As a result, arguments about who has the 'right' typology are misplaced. We urge caution in using these country classifications in structuring qualitative inquiry and discourage their usage as indicator variables in quantitative analysis, especially in the context of time-series cross-section data. We argue that the real value of both Esping-Andersen's work and the Varieties of Capitalism project consists of their theoretical contributions and heuristic classification of ideal types." (author's abstract)"In der vergleichenden Politischen Ökonomie reicher Demokratien gibt es eine lange Tradition, Länder aufgrund ihrer unterschiedlichen wirtschaftlichen Institutionen und Policies zu typologisieren. Die jüngste dieser Typologien - das 'Varieties-of-Capitalism'-Konzept - erfasst zwei Gruppen von Ländern: koordinierte und liberale Marktwirtschaften. Da diese Klassifizierung einige Kontroversen hervorgerufen hat, nutzen die Autoren neueste Fortschritte im 'mixture model-based clustering', um zu prüfen, welche Erkenntnisse die Daten zu diesem Problem liefern. Die Ergebnisse weisen eine beträchtliche Unsicherheit hinsichtlich der Anzahl der Cluster und, mit wenigen Ausnahmen, der Zuordnung der Länder zu Clustern auf. Betrachtet man größere Zeiträume, variieren darüber hinaus die Anzahl der Cluster und Ländermitgliedschaften erheblich. Als Folge dieser Befunde halten die Autoren Argumentationen über die 'richtige' Typologisierung für unangebracht und raten davon ab, diese Länderklassifizierungen zur Strukturierung qualitativer Studien heranzuziehen oder als Indikatorvariablen in quantitativen Analysen zu nutzen. Dies gilt insbesondere im Kontext von gepoolten Zeitreihen- und Querschnittsdaten. Sie argumentieren, dass der substanzielle Wert sowohl der Forschung von Esping-Andersen als auch des 'Varieties-of-Capitalism'-Ansatzes in den Beiträgen zur Theorie und den heuristischen Klassifizierungen von Idealtypen besteht." (Autorenreferat

Can students be encouraged to read? Experimental evidence from a large lecture

One of the structural problems of introductory lectures is that students’ learning progress is primarily assessed by taking a final exam. Weekly preparation and reading are driven only by self-motivation. Can a student’s decision to complete her weekly assignments be influenced by a simple reminder? In a pre-registered experimental design, we test if personalised reminders from the instructor delivered via text messages contribute to learning outcomes. We assess formative learning via regular quizzes at the beginning of each class, and summative learning via grades in a final exam. We do not find statistically significant differences in learning outcomes, and discuss how design features potentially drive this result. In the conclusion, we stress the importance of experimental design in assessing innovative and new learning techniques

Geospatial Information Research: State of the Art, Case Studies and Future Perspectives

Geospatial information science (GI science) is concerned with the development and application of geodetic and information science methods for modeling, acquiring, sharing, managing, exploring, analyzing, synthesizing, visualizing, and evaluating data on spatio-temporal phenomena related to the Earth. As an interdisciplinary scientific discipline, it focuses on developing and adapting information technologies to understand processes on the Earth and human-place interactions, to detect and predict trends and patterns in the observed data, and to support decision making. The authors – members of DGK, the Geoinformatics division, as part of the Committee on Geodesy of the Bavarian Academy of Sciences and Humanities, representing geodetic research and university teaching in Germany – have prepared this paper as a means to point out future research questions and directions in geospatial information science. For the different facets of geospatial information science, the state of art is presented and underlined with mostly own case studies. The paper thus illustrates which contributions the German GI community makes and which research perspectives arise in geospatial information science. The paper further demonstrates that GI science, with its expertise in data acquisition and interpretation, information modeling and management, integration, decision support, visualization, and dissemination, can help solve many of the grand challenges facing society today and in the future

Fasudil Loaded PLGA Microspheres as Potential Intravitreal Depot Formulation for Glaucoma Therapy

Rho-associated protein kinase (ROCK) inhibitors allow for causative glaucoma therapy. Unfortunately, topically applied ROCK inhibitors suffer from high incidence of hyperemia and low intraocular bioavailability. Therefore, we propose the use of poly (lactide-co-glycolide) (PLGA) microspheres as a depot formulation for intravitreal injection to supply outflow tissues with the ROCK inhibitor fasudil over a prolonged time. Fasudil-loaded microspheres were prepared by double emulsion solvent evaporation technique. The chemical integrity of released fasudil was confirmed by mass spectrometry. The biological activity was measured in cell-based assays using trabecular meshwork cells (TM cells), Schlemm's canal cells (SC cells), fibroblasts and adult retinal pigment epithelium cells (ARPE-19). Cellular response to fasudil after its diffusion through vitreous humor was investigated by electric cell-substrate impedance sensing. Microspheres ranged in size from 3 to 67 mu m. The release of fasudil from microspheres was controllable and sustained for up to 45 days. Released fasudil reduced actin stress fibers in TM cells, SC cells and fibroblasts. Decreased collagen gel contraction provoked by fasudil was detected in TM cells (similar to 2.4-fold), SC cells (similar to 1.4-fold) and fibroblasts (similar to 1.3-fold). In addition, fasudil readily diffused through vitreous humor reaching its target compartment and eliciting effects on TM cells. No negative effects on ARPE-19 cells were observed. Since fasudil readily diffuses through the vitreous humor, we suggest that an intravitreal drug depot of ROCK inhibitors could significantly improve current glaucoma therapy particularly for patients with comorbid retinal diseases

Modeling plasticity and dysplasia of pancreatic ductal organoids derived from human pluripotent stem cells

Personalized in vitro models for dysplasia and carcinogenesis in the pancreas have been constrained by insufficient differentiation of human pluripotent stem cells (hPSCs) into the exocrine pancreatic lineage. Here, we differentiate hPSCs into pancreatic duct-like organoids (PDLOs) with morphological, transcriptional, proteomic, and functional characteristics of human pancreatic ducts, further maturing upon transplantation into mice. PDLOs are generated from hPSCs inducibly expressing oncogenic GNAS, KRAS, or KRAS with genetic covariance of lost CDKN2A and from induced hPSCs derived from a McCune-Albright patient. Each oncogene causes a specific growth, structural, and molecular phenotype in vitro. While transplanted PDLOs with oncogenic KRAS alone form heterogenous dysplastic lesions or cancer, KRAS with CDKN2A loss develop dedifferentiated pancreatic ductal adenocarcinomas. In contrast, transplanted PDLOs with mutant GNAS lead to intraductal papillary mucinous neoplasia-like structures. Conclusively, PDLOs enable in vitro and in vivo studies of pancreatic plasticity, dysplasia, and cancer formation from a genetically defined background

Imaging Erythrocyte Sedimentation in Whole Blood

The erythrocyte sedimentation rate (ESR) is one of the oldest medical diagnostic tools. However, currently there is some debate on the structure formed by the cells during the sedimentation process. While the conventional view is that erythrocytes sediment as separate aggregates, others have suggested that they form a percolating gel, similar to other colloidal suspensions. However, visualization of aggregated erythrocytes, which would settle the question, has always been challenging. Direct methods usually study erythrocytes in 2D situations or low hematocrit (∼1%). Indirect methods, such as scattering or electric measurements, provide insight on the suspension evolution, but cannot directly discriminate between open or percolating structures. Here, we achieved a direct probing of the structures formed by erythrocytes in blood at stasis. We focused on blood samples at rest with controlled hematocrit of 45%, from healthy donors, and report observations from three different optical imaging techniques: direct light transmission through thin samples, two-photon microscopy and light-sheet microscopy. The three techniques, used in geometries with thickness from 150 μm to 3 mm, highlight that erythrocytes form a continuous network with characteristic cracks, i.e., a colloidal gel. The characteristic distance between the main cracks is of the order of ∼100 μm. A complete description of the structure then requires a field of view of the order of ∼1 mm, in order to obtain a statistically relevant number of structural elements. A quantitative analysis of the erythrocyte related processes and interactions during the sedimentation need a further refinement of the experimental set-ups

Solid-phase-assisted synthesis of targeting peptide-PEG-oligo(ethane amino)amides for receptor-mediated gene delivery.

In the forthcoming era of cancer gene therapy, efforts will be devoted to the development of new efficient and non-toxic gene delivery vectors. In this regard, the use of Fmoc/Boc-protected oligo(ethane amino)acids as building blocks for solid-phase-supported assembly represents a novel promising approach towards fully controlled syntheses of effective gene vectors. Here we report on the synthesis of defined polymers containing the following: (i) a plasmid DNA (pDNA) binding domain of eight succinoyl-tetraethylenpentamine (Stp) units and two terminal cysteine residues; (ii) a central polyethylene glycol (PEG) chain (with twenty-four oxyethylene units) for shielding; and (iii) specific peptides for targeting towards cancer cells. Peptides B6 and c(RGDfK), which bind transferrin receptor and αvβ3 integrin, respectively, were chosen because of the high expression of these receptors in many tumoral cells. This study shows the feasibility of designing these kinds of fully controlled vectors and their success for targeted pDNA-based gene transfer

Spatiotemporal analysis of Indian megacities

Urbanization is arguably the most dramatic form of highly irreversible land transformation. While urbanization is a worldwide phenomenon, it is exceptionally dynamic in India, where unprecedented urban growth rates have occurred over the last 30 years. In this uncontrolled explosive situation city planning lacks of data and information to measure, monitor, understand urban sprawl processes. The analysis of such changes has become an important use of multitemporal remote sensing data. Using a time-series of Landsat data to classify the urban footprints since the 1970s enables detection of temporal and spatial urban sprawl, redensification and urban development in the explosively growing large urban agglomerations of the mega cities Mumbai, Delhi and Kolkata in India. Combining gradient analysis with landscape metrics the spatiotemporal pattern of urbanization are quantified. Spatial parameters are the absolute areal growth, urbanization rates, built-up densities, landscape shape index, edge density, patch density, or largest patch index. The study aims to detect analogies and differences for spatial growth in Indian mega cities, cities in the same cultural area at about the same development stage regarding absolute population. The results paint a characteristic picture of spatial pattern gradients and landscape metrics of the three Indian mega cities