| 1. |
- Henrekson, Ebba, et al.
(författare)
-
Civil Society Regimes and School Choice Reforms : Evidence from Sweden and Milwaukee
- 2020
-
Ingår i: Nonprofit Policy Forum. - : Walter de Gruyter GmbH. - 2154-3348 .- 2194-6035. ; 11:1, s. 1-37
-
Tidskriftsartikel (refereegranskat)abstract
- We examine the effects of school choice reforms implemented in the early 1990s in two different settings: Sweden and Milwaukee (WI, U.S.). We show how both the ideological and theoretical arguments for choice reform were similar in the two contexts, yet the consequences in terms of the organizational outcome and institutional sector configuration ended up strikingly dissimilar. While the new group of actors in the Swedish school system consisted primarily of large-scale for-profit schools, with only a minor share of the expansion being catered to by nonprofit actors, the Milwaukee school choice program became dominated by small-scale nonprofit schools operated by religious communities. We seek to explicate these differences by drawing on the welfare state literature and social origins theory, as well as from organizational and historical institutional theory. We argue that the resulting composition of providers is directly related to the deep-seated differences in the civil society regimes operating in the two contexts.
|
|
| 2. |
- Yuan, Jianyu, et al.
(författare)
-
Comparing the device physics, dynamics and morphology of polymer solar cells employing conventional PCBM and non-fullerene polymer acceptor N2200
- 2017
-
Ingår i: Nano Energy. - : ELSEVIER SCIENCE BV. - 2211-2855 .- 2211-3282. ; 35, s. 251-262
-
Tidskriftsartikel (refereegranskat)abstract
- Current all polymer solar cells still suffer from low fill factors (FF) and short-circuit current density (J(sc)) compared with the conventional polymer/fullerene system. Herein in this work, devices using PTP8 as the electron donor and [70]PCBM as well as widely used polymer N2200 as the electron acceptor were systematically studied and compared. The major loss mechanisms in the all polymer solar cells were investigated to understand their relatively lower performance than the PTP8/fullerene system. By performing in-depth analysis on ultrafast transient transmission spectroscopy results, we estimated that in PTP8/N2200 device nearly half of the charges recombine geminately, which is confirmed as the major factor hindering the device performance of all polymer solar cells compared with polymer/fullerene system. Through thorough morphology analysis, the low charge generation efficiency is attributed to the reduced crystallinity of N2200 in the blend film and the unfavorable face-to-edge orientation at the donor/acceptor heterojunction. Coupling these results with knowledge from efficient polymer/fullerene systems, the future design of new polymers can devote to increase the attraction between the pi face of donor and acceptor, leading to enhanced face-to-face orientation at the heterojunction, while maintaining a high pi-pi stacking order for each polymer.
|
|
| 3. |
- Morin, Phillip A., et al.
(författare)
-
Geographic and temporal dynamics of a global radiation and diversification in the killer whale
- 2015
-
Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 24:15, s. 3964-3979
-
Tidskriftsartikel (refereegranskat)abstract
- Global climate change during the Late Pleistocene periodically encroached and then released habitat during the glacial cycles, causing range expansions and contractions in some species. These dynamics have played a major role in geographic radiations, diversification and speciation. We investigate these dynamics in the most widely distributed of marine mammals, the killer whale (Orcinus orca), using a global data set of over 450 samples. This marine top predator inhabits coastal and pelagic ecosystems ranging from the ice edge to the tropics, often exhibiting ecological, behavioural and morphological variation suggestive of local adaptation accompanied by reproductive isolation. Results suggest a rapid global radiation occurred over the last 350000years. Based on habitat models, we estimated there was only a 15% global contraction of core suitable habitat during the last glacial maximum, and the resources appeared to sustain a constant global effective female population size throughout the Late Pleistocene. Reconstruction of the ancestral phylogeography highlighted the high mobility of this species, identifying 22 strongly supported long-range dispersal events including interoceanic and interhemispheric movement. Despite this propensity for geographic dispersal, the increased sampling of this study uncovered very few potential examples of ancestral dispersal among ecotypes. Concordance of nuclear and mitochondrial data further confirms genetic cohesiveness, with little or no current gene flow among sympatric ecotypes. Taken as a whole, our data suggest that the glacial cycles influenced local populations in different ways, with no clear global pattern, but with secondary contact among lineages following long-range dispersal as a potential mechanism driving ecological diversification.
|
|
