Structural variants of biodegradable polyesterurethane in vivo evoke a cellular and angiogenic response that is dictated by architecture

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2008 Acta Materialia Inc.The aim of this study was to investigate an in vivo tissue response to a biodegradable polyesterurethane, specifically the cellular and angiogenic response evoked by varying implant architectures in a subcutaneous rabbit implant model. A synthetic biodegradable polyesterurethane was synthesized and processed into three different configurations: a non-porous film, a porous mesh and a porous membrane. Glutaraldehyde cross-linked bovine pericardium was used as a control. Sterile polyesterurethane and control samples were implanted subcutaneously in six rabbits (n = 12). The rabbits were killed at 21 and 63 days and the implant sites were sectioned and histologically stained using haemotoxylin and eosin (H&E), Masson’s trichrome, picosirius red and immunostain CD31. The tissue–implant interface thickness was measured from the H&E slides. Stereological techniques were used to quantify the tissue reaction at each time point that included volume fraction of inflammatory cells, fibroblasts, fibrocytes, collagen and the degree of vascularization. Stereological analysis inferred that porous scaffolds with regular topography are better tolerated in vivo compared to non-porous scaffolds, while increasing scaffold porosity promotes angiogenesis and cellular infiltration. The results suggest that this biodegradable polyesterurethane is better tolerated in vivo than the control and that structural variants of biodegradable polyesterurethane in vivo evoke a cellular and angiogenic response that is dictated by architecture.Irish Research Council for Science, Engineering and Technology: funded by the National Development Plan. Enterprise Ireland: Research Innovation Partnership

Überprüfung einer Typologie der Klassenführung

Lehrerverhalten im Unterricht vollzieht sich gleichzeitig auf der inhaltlichen und der sozialen Ebene. Um die soziale Ordnung im Unterricht zu erhalten, führen Lehrpersonen die Klasse, indem sie Regeln setzen und sich adaptiv und flexibel verhalten. Daraus werden die vier Typen souveräne, regelgeleitete, situationsspezifische und desorganisierte Klassenführung abgeleitet. Anhand einer Fragebogenuntersuchung mit 183 Lehrpersonen und 454 Schülerinnen und Schülern der 6. Klassenstufe wurde diese Typologie überprüft. Die souveräne Klassenführung erforderte besonders hohe Kompetenzen und implizierte Bildungs- und Beziehungswerte. Mehrebenenanalysen bestätigten den Einfluss der Klassenführung auf die Lehrerwahrnehmung der Schülerinnen und Schüler sowie auf die Schülerleistungen in Mathematik. (DIPF/Orig.)Classroom teacher management behavior depends on both the class content level and the social level. To establish social order in classrooms teachers set rules and behave adaptively and flexibly. On both dimensions of classroom management we described four types: sovereign, rule guided, situation specific and desorganized classroom management. These types were examined by a questionnaire study with 183 teachers and 454 students from 6th grade. The sovereign management conditions high competences and high educational and relation oriented values. Multilevel analyses confirmed the influence of classroom management on student perceptions of their teachers and on student achievement in math. (DIPF/Orig.

Reconstituting a rainforest patch in southern Benin for the protection of threatened plants

In a twenty-year effort at Drabo, southern Benin, small remnant forests, young fallow and agricultural fields were linked and rehabilitated to develop a 14 ha forest reserve. Forest regrowth was encouraged by managing the natural growth of the local fallow vegetation and by bringing in seeds and other propagules from forest islands of Benin. The succession to shade-tolerant woody forest species of Guineo-Congolian origin at the expense of extra-regional herbs, the co-existence of species with slightly different requirements, and the fate of exotic trees in this natural forest are described. A quantitative assessment of a homogeneous lot indicated 397 trees per ha, with stem diameters >10 cm, 43.7% of them below 20 cm, and a rich undergrowth of 72600 smaller plants per ha, proof of active rejuvenation. Only 4.2% of all plants resulted from the 1041 introduction events, i.e., species per date, mostly of the 253 plant species that were new to Drabo. A total of 635 species were recorded, but 50 did not survive and four are yet to be identified. In June 2016, the total of 581 known living species included 224 trees. Among all plants, 244 hailed from the Guineo-Congolian zone with 17 of Upper Guinean and four of Lower Guinean origin, 113 from the three savannah zones, and 224 were of extra-regional origin. Overall, 72.8% of all woody plants, such as many climbers, all shrubs and trees, were of forest and savanna origin (GC, SG, SZ and S), whereas 70.4% of all herbs came from other regions (At, PAL and Pt). Only 7.0% of all species from the GC zone were in decline; but the further away the plants originated from, the larger the decline in numbers and vigour, up to 64.6% among plants of pan-tropical origin. Particularly pan-tropical herbs became ever rarer, with 80.0% of them declining and confined to the few open spaces along paths. In 2017 the forest harboured 52 threatened species, with threat categories EW, CR, EN or VU on the Red List of Benin, out of 73 IUCN-listed species that could possibly survive in Drabo. Some of these species occur in only one or two other locations in Benin. The biodiversity richness of the rehabilitated forests of Drabo now rivals that of natural rainforest remnants of the region. As the surrounding landscape becomes ever more impoverished because of the high human population and its ever increasing impact, the maintenance of such managed islands of biodiversity is critical. By establishing rare local species from other locations we can compensate for direct human destruction and long-term stochastic loss of species in this highly fragmented landscape where natural seed dispersal is difficult

Role of the Predator Hemerobius pacificus in a Non-Insecticide Treated Artichoke Field

Hemerobius pacificus oviposition closely followed the population densities of Myzus persicae which peaked in late fall and declined to zero in spring in an untreated artichoke field. A second peak of oviposition by the predator followed the increasing populations of the artichoke plume moth (=APM), Platyptilia carduidactyla in spring. Where Hemerobius eggs were released, the aphid populations were reduced consistently, while the APM damage was reduced only at larval infestation levels of APM above 10%. Oviposition by wild Hemerobius was lower in plots where aphids had been reduced by released predators. APM infestations were estimated to be lowered by 30% by wild Hemerobius populations, while hymenopterous parasites accounted for 14% of the larval mortality of APM. Protein + sugar food sprays applied 5 times during the year slightly increased Hemerobius oviposition which in turn led to lower aphid populations and slightly reduced APM infestations. Hemerobius, the only common active predator in artichokes during winter, is considered an important control agent of aphids under cool conditions, and is a mortality factor of APM larvae. Hemerobius should be preserved in integrated control program

Selektionsprozesse beim Übergang in die Sekundarstufe I und II

Zusammenfassung: Ziel der Studie ist es, die Bedeutung den Einfluss Umfelds, der Noten und Leistungen sowie des Sozialverhaltens von Schülerinnen und Schülern im Unterricht auf Bildungsverläufe zu untersuchen. Im Rahmen des Forschungsprojekts Familie-Schule-Beruf (FASE B) wurde eine repräsentative Längsschnittstichprobe von 454 Schülerinnen und Schülern und deren primären Bezugspersonen im Kanton Bern (Schweiz) genutzt. In stufenweisen logistischen Regressionsanalysen wurde untersucht, wie familiäre und individuelle Determinanten am Ende der Primarschule das Schulniveau in die Sekundarstufe I und den weiteren Bildungsverlauf in die Sekundarstufe II (Gymnasium vs. Berufsbildung) vorhersagten. Der Übertritt in die Sekundarstufe I hing stärker von Noten als von Leistungstestergebnissen ab. Elternerwartungen, Schichtzugehörigkeit und Verhaltensauffälligkeiten im Unterricht waren ebenfalls bedeutsam. Elternerwartungen sagten den Bildungsverlauf über zwei Schultransitionen hinweg vorher, während Noten in Deutsch und das Geschlecht nur tendenziell signifikant waren. Elternerwartungen erlauben präzise Vorhersagen von Bildungsverläufen über zwei Schultransitionen, auch nach Kontrolle von Noten und Leistungen der Kinde

Long-term conservation and rehabilitation of threatened rain forest patches under different human population pressures in West Africa

The management schemes of four rain forest patches in southern Benin and south-western Nigeria, which led to the successful protection of numerous threatened plants and animals over the last 20 plus years, are analysed. Since climatic conditions are similar, tree composition depends largely on different availability of water and documented biodiversity mostly on the availability of taxonomic expertise. Management differs according to accessibility and human population pressure, from total closing off of the forest by an international institute near the mega-polis Ibadan to unmarked borders near Lanzron, a remote village in the lower Ouémé Valley, where foreigners are mostly excluded from visiting the site. In Benin, trees and wildlife (antelopes and monkeys) seem best protected where the local vodoun beliefs are adhered to. This is, however, not sufficient and development aid to support and benefit the local population is needed as exemplified in Zinvié. At the Ibadan and Drabo sites, long-term protection is assured by legally-binding land-titles. Since for all of Lanzron and part of Zinvié these are lacking securing them is a priority. In Ibadan, Nigeria, a major rehabilitation effort is concentrated on bringing relatively old grass land and former village sites under forest cover by planting local trees. Rehabilitation in Drabo, in southern Benin, relies on enriching the naturally occurring fallow succession with rare species from nearby threatened sacred forests. We demonstrate that reversing biodiversity loss is possible but requires a long-term commitment. Recommendations for protecting, stabilizing and enhancing similar small hotspots of biodiversity are made