Forschendes Lernen. Konzeptuelle Grundlagen und Potenziale digitaler Medien

Im folgenden Artikel wird dargelegt, was unter dem Konzept des forschenden Lernens zu verstehen ist und welche Einsatzmöglichkeiten sich für das forschende Lernen im Kontext Universität ergeben. Dabei werden speziell diejenigen Merkmale theoretisch herausgearbeitet, die aus Lehrendenperspektive Anknüpfungspunkte für einen prozessbegleitenden Medieneinsatz bieten. Exemplarisch wird eine Lehrveranstaltung angeführt, die auf Fallebene zeigt, wie ein forschungsorientiertes Seminar um digitale Medien angereichert werden kann und welche Chancen und Grenzen sich bei der selbstgesteuerten Verwendung digitaler Medienangebote ergeben. Die Evaluation des Seminars zeigt, dass die Studierenden einen großen Lernzuwachs erleben, jedoch teilweise durch die Offenheit des Lernens überfordert sind. Diese und andere Gründe führen dazu, dass die von Lehrenden vorgeschlagenen Medienangebote selten bis kaum genutzt werden. Zudem sehen Lernende die Qualität virtuell distribuierter Inhalte kritisch, was sich auf die Akzeptanz und die Nutzung der vorhandenen digitalen Medienangebote auswirkt. (DIPF/Orig.

Immunoglobulin M nephropathy: Histopathological and clinical characteristics. Case series

La nefropatía por inmunoglobulina M (NIgM) es una glomerulopatía idiopática caracterizada por depósitos mesangiales globales y difusos de IgM. Se realizó un estudio retrospectivo de las características clínicas e histopatológicas de los pacientes con NIgM atendidos en nuestro servicio. De 241 biopsias renales, 21 correspondieron a NIgM (8,7 %). Se incluyeron 18 pacientes (14 de sexo femenino, mediana de edad: 3,08 años). Se excluyó a 1 paciente por enfermedad sistémica asociada y a 2 por seguimiento menor a 1 año. Catorce pacientes se manifestaron con síndrome nefrótico (SN) y 4 con proteinuria aislada o asociada a hematuria. En la microscopia óptica, 13 presentaron hiperplasia mesangial, y 5 esclerosis focal y segmentaria. De los pacientes con SN, 7 fueron corticorresistentes, 4 corticodependientes y 3 presentaban recaídas frecuentes. Todos los pacientes con SN y 1 con proteinuria-hematuria recibieron inmunosupresores; los 18 pacientes recibieron, además, antiproteinúricos. Luego de 5,2 años (2-17,5) de seguimiento, 6 pacientes evolucionaron a enfermedad renal crónica.Immunoglobulin M nephropathy (IgMN) is an idiopathic glomerulopathy characterized by diffuse global mesangial deposits of IgM. We retrospectively studied the clinical and histopathological characteristics of the patients with IgMN seen in our service. Of 241 renal biopsies, 21 corresponded to IgMN (8.7 %). One patient was excluded due to associated systemic disease and 2 due to follow-up less than 1 year, 18 were included (14 girls, median age 3.08 years). Fourteen manifested with nephrotic syndrome (NS) and the remaining with proteinuria (isolated or associated with hematuria). On light microscopy, 13 had hyperplasia with mesangial expansion and 5 had focal and segmental sclerosis. Of the patients with NS, 7 were steroid-resistant, 4 steroid-dependent, and 3 frequent relapsers. All patients with NS and 1 with proteinuria-hematuria received immunosuppressants; the 18 patients also received antiproteinuric drugs. After 5.2 years (2-17.5) of follow-up, 6 patients developed chronic kidney disease.Fil: Meni Battaglia, Luciana. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Balestracci, Alejandro. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Toledo, Ismael. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Martin, Sandra M.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Careaga, Claudia Mabel. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Gogorza, María C.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Caupolican, Alvarado. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Cao, Gabriel Fernando. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Data for: ROCK-MAGNETIC AND PALEOMAGNETIC STUDIES ON LATE-HOLOCENE SEDIMENTS FROM LAGUNA CHÁLTEL (PATAGONIA, ARGENTINA)

Data PSV-RPI, Laguna CháltelTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Vehicle-derived emissions and pollution on the road autovia 2 investigated by rock-magnetic parameters: A case study from Argentina

35 Pag., 7 Fig., 1 Tabl. The definitive version is available at: www.springerlink.comIn this work, we carried out a preliminary study of traffic-derived pollutants from primary sources (vehicles), and on roads (paved area), road borders and surroundings areas. The study is focussed on the identification, distribution and concentration of pollutants and magnetic carriers. Magnetic parameters and their analyses suggest that the magnetic signal of vehicle-derived emissions is controlled by a magnetite-like phase. Magnetic grain size estimations reveal the presence of fine particles (0.1–5 μm) that can be inhaled and therefore are dangerous to human health. Magnetic susceptibility results (about 175 × 10−5 SI) show a higher magnetic concentration — magnetic enhancement — in the central area of the tollbooth line that is related to higher traffic. In addition, magnetic susceptibility was computed on several roadside soils along a length of 120 km and used to generate a 2-D contour map, which shows higher magnetic values (100–200 10−5 SI) near the edge of the road. The observed distribution of magnetic values indicates that magnetic particles emitted by vehicles are accumulated and mainly concentrated within a distance of several meters (1–2 m) from the edge of the road. In consequence, the magnetic susceptibility parameter seems to be a suitable indicator of traffic-related pollution. Non-magnetic studies show an enrichment of some trace elements, such as Ba, Cr, Cu, Zn and Pb, that are associated with traffic pollution. Furthermore, statistical correlations between the content of toxic trace metals and magnetic variables support the use of magnetic parameters as potential proxies for traffic-related pollution in this study area.D. Marié was supported by two Fellowships (2005-2006, 2008) from the Comisión de Investigaciones Científicas de la Pcia. de Buenos Aires (CICPBA) and the Inter U program. Financial support was also received from a PICT-2005 of the ANPCYT, project No. 38050.Peer reviewe

Magnetic studies and scanning electron microscopy — X-ray energy dispersive spectroscopy analyses of road sediments, soils and vehicle-derived emissions

27 Pag., 2 Tabl., 6 Fig. The definitive version is available at: http://www.springerlink.com/content/0039-3169/Human health and environmental problems related to particulate matter emission from vehicles has become a topic of research interest in recent years. These airborne particles can not only be directly inhaled, but are also present as suspended and deposited particles on paved areas and roadside soils. Here we report on magnetic studies, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and chemical analyses of vehicle-derived particles collected from both primary sources and as deposited particles on roads and soils. Preliminary results, recently published by the authors, have revealed that the magnetic signal of such particles is controlled by a magnetite-like phase with magnetic grain size ranging between 0.1 µm and 5 µm. An enrichment of some trace elements: Ba, Cr, Cu, Zn and Pb was also found. In this study we focus on SEM and EDS complementary studies of magnetic extracts. SEM observations showed small individual particles or spherulites, small aggregates in the form of chains or clusters, large aggregates of spherules, flake-like bodies, fibre-like particles, sheet-like particles, irregular debris and large particle agglomerates, i.e. a wide variety of shapes. Grain size distribution is also in agreement with magnetic grain size estimations. Additionally the following elements: C, O, Na, Mg, Al, Si, S, K, Ca, V, Ba, Ti, Cr, Mn, Fe, Cu, Zn and Pb were detected by EDS analysis.The authors would like to thank the CONICET, UNCPBA and UNMdP. Financial support was also received from a PICT-2005 of the ANPCYT, project No. 38050 and by the CICYT project MEDEROCAR (CGL2008-0831).Peer reviewe