Microbiota composition of simultaneously colonized mice housed under either a gnotobiotic isolator or individually ventilated cage regime

Germ-free rodents colonized with microbiotas of interest are used for host-microbiota investigations and for testing microbiota-targeted therapeutic candidates. Traditionally, isolators are used for housing such gnotobiotic rodents due to optimal protection from the environment, but research groups focused on the microbiome are increasingly combining or substituting isolator housing with individually ventilated cage (IVC) systems. We compared the effect of housing systems on the gut microbiota composition of germ-free mice colonized with a complex microbiota and housed in either multiple IVC cages in an IVC facility or in multiple open-top cages in an isolator during three generations and five months. No increase in bacterial diversity as assessed by 16S rRNA gene sequencing was observed in the IVC cages, despite not applying completely aseptic cage changes. The donor bacterial community was equally represented in both housing systems. Time-dependent clustering between generations was observed in both systems, but was strongest in the IVC cages. Different relative abundance of a Rikenellaceae genus contributed to separate clustering of the isolator and IVC communities. Our data suggest that complex microbiotas are protected in IVC systems, but challenges related to temporal dynamics should be addressed

Gastrointestinal microbiota and local inflammation during oxazolone-induced dermatitis in BALB/cA Mice

At present, laboratory animals are not standardized with regard to the gastrointestinal microbiota (GM), but differences in this feature may alter various parameters in animal models. We hypothesized that variation in the GM correlated with variation in clinical parameters of a murine oxazolone-induced skin inflammation model of atopic dermatitis. BALB/cA mice were sensitized with oxazolone over a 28-d period and variation in gastrointestinal microbiota in fecal and cecal samples was assessed by PCR-denaturing gradient gel electrophoresis. Clinical parameters included transepidermal water loss, ear thickness, inflammatory factors in ear tissue and plasma, and histopathologic evaluation. The fecal microbiota before induction of skin inflammation strongly correlated with the levels of some proinflammatory cytokines (IFNγ, IL1β, IL12, and TNFα), the antiinflammatory cytokines IL4 and IL10, and the chemokine KC/GRO that were measured in ear samples at study termination. Cecal microbiota at termination correlated with ear thickness and transepidermal water loss. There was no correlation between cytokine responses and ear thickness or transepidermal water loss. In addition, GM changed during the study period in the oxazolone-treated mice, whereas this was not the case for the control mice. The current study shows that the GM of mice influences the development of oxazolone-induced skin inflammation and that the model itself likely induces a pathophysiologic response that alters the composition of the GM

A Humanized Diet Profile May Facilitate Colonization and Immune Stimulation in Human Microbiota-Colonized Mice

Background: In spite of the importance of the use of gnotobiotic mice for human fecal transfer, colonization efficiency and immune stimulation after human microbiota inoculation in mice are poorly studied compared to mouse microbiota inoculation. We tested the colonization efficiency and immune responses in mice bred for one additional generation after inoculating the parent generation with either a human (HM) or a mouse microbiota (MM). Furthermore, we tested if colonization efficiency and immune stimulation could be improved in HM-colonized mice by dietary approaches: if these were fed a diet closer to the human diet either in its sources of animal fat and protein [the “animal source” (AS) diet] or in its proportions of macronutrients from the normal sources of a mouse diet [the “human profile” (HP) diet]. Results: Although significantly lower in mice with a human microbiota (30–40% vs. 61– 70%) the colonization efficiency was significantly higher in HM mice fed the HP diet (40%), and in MM mice fed AS (70%). The microbiota of mice fed HP was comparable to the microbiota of mice fed a standard rodent chow, while the microbiota of mice fed the animal source diet (AS) clustered separately. Mice inoculated with mouse fecal matter had significantly more CD4+ T cells and Cd4 expression and significantly fewer regulatory T cells (Tregs) and FoxP3 expression than human microbiota inoculated mice, but cell proportions differences were mostly apparent between mice fed the AS diet. Mice fed the HP diet had significantly higher expression of Cd8a. Conclusion: It is concluded that a diet with a humanized profile could support the establishment of a human microbiota in mice, which will, however, still elicit a lower colonization efficiency compared to mice inoculated with a mouse microbiota.The work was funded by the Innovation Fund Denmark (Grant No. 1355-00004B) and Taconic Biosciences. IM-I was funded during the experimental work by a fellowship associated to her Sara Borrell postdoctoral contract (CD12/00530), and nowadays is supported by a Miguel Servet contract (CP16/00163) both from Instituto de Salud Carlos III co-founded by Fondo Europeo de Desarrollo Regional – FEDER.Ye

Knowledge Claims and Struggles in Decentralized Large Carnivore Governance : Insights From Norway and Sweden

Ensuring sustainable carnivore populations while simultaneously sustaining active and viable pastoral communities often creates conflicts that are difficult to resolve. This article examines how different knowledge systems meet and interact in large carnivore governance in Norway and Sweden. Drawing on a broad range of sources, including observations in meetings, public documents, reports and interviews, in addition to local and national newspaper clippings and internet sites, we study two processes of regional carnivore management (Nordland, Norway and Jämtland, Sweden). We explore how different forms of knowledge have been mobilized, reproduced, transferred and legitimized in policies and regulations in these two processes. Furthermore, we examine the interplay between scientific and experience-based knowledge at different levels and scales in both countries. In Norway, “clear zoning” has been established as a basic management instrument to achieve national “population goals” for carnivores. We show how the locally situated knowledge – in our account represented through the Regional Large Carnivore Committee (RLCC), which includes political parties’ and Sami Parliament representatives – experiences real barriers by being overruled by the national Ministry of Climate and Environment, 2016 in their process of revising the carnivore management plan (CMP). In Sweden where the management of large carnivores is devolved to regional authorities and stakeholder-based Wildlife Management Delegations (WMDs), attempts to regionally solve conflicts are often overthrown by the national environmental protection agency or through court cases initiated by the environmental movement. Hence, compromises that potentially could solve conflicts are undermined. The analysis shows that while carnivore governance in both countries are founded on decentralized management authority at the regional level, local actors struggle for their views, experiences and knowledge to be acknowledged and counted as valid in the management process. While the decentralized management model opens for inclusion of different knowledge systems, this system has yet to acknowledge the challenges of knowledge being dismissed or marginalized across governance levels and scales

Knowledge Claims and Struggles in Decentralized Large Carnivore Governance: Insights From Norway and Sweden

Ensuring sustainable carnivore populations while simultaneously sustaining active and viable pastoral communities often creates conflicts that are difficult to resolve. This article examines how different knowledge systems meet and interact in large carnivore governance in Norway and Sweden. Drawing on a broad range of sources, including observations in meetings, public documents, reports and interviews, in addition to local and national newspaper clippings and internet sites, we study two processes of regional carnivore management (Nordland, Norway and Jämtland, Sweden). We explore how different forms of knowledge have been mobilized, reproduced, transferred and legitimized in policies and regulations in these two processes. Furthermore, we examine the interplay between scientific and experience-based knowledge at different levels and scales in both countries. In Norway, “clear zoning” has been established as a basic management instrument to achieve national “population goals” for carnivores. We show how the locally situated knowledge – in our account represented through the Regional Large Carnivore Committee (RLCC), which includes political parties’ and Sami Parliament representatives – experiences real barriers by being overruled by the national Ministry of Climate and Environment, 2016 in their process of revising the carnivore management plan (CMP). In Sweden where the management of large carnivores is devolved to regional authorities and stakeholder-based Wildlife Management Delegations (WMDs), attempts to regionally solve conflicts are often overthrown by the national environmental protection agency or through court cases initiated by the environmental movement. Hence, compromises that potentially could solve conflicts are undermined. The analysis shows that while carnivore governance in both countries are founded on decentralized management authority at the regional level, local actors struggle for their views, experiences and knowledge to be acknowledged and counted as valid in the management process. While the decentralized management model opens for inclusion of different knowledge systems, this system has yet to acknowledge the challenges of knowledge being dismissed or marginalized across governance levels and scales

Knowledge Claims and Struggles in Decentralized Large Carnivore Governance: Insights From Norway and Sweden

Ensuring sustainable carnivore populations while simultaneously sustaining active and viable pastoral communities often creates conflicts that are difficult to resolve. This article examines how different knowledge systems meet and interact in large carnivore governance in Norway and Sweden. Drawing on a broad range of sources, including observations in meetings, public documents, reports and interviews, in addition to local and national newspaper clippings and internet sites, we study two processes of regional carnivore management (Nordland, Norway and Jämtland, Sweden). We explore how different forms of knowledge have been mobilized, reproduced, transferred and legitimized in policies and regulations in these two processes. Furthermore, we examine the interplay between scientific and experience-based knowledge at different levels and scales in both countries. In Norway, “clear zoning” has been established as a basic management instrument to achieve national “population goals” for carnivores. We show how the locally situated knowledge – in our account represented through the Regional Large Carnivore Committee (RLCC), which includes political parties’ and Sami Parliament representatives – experiences real barriers by being overruled by the national Ministry of Climate and Environment, 2016 in their process of revising the carnivore management plan (CMP). In Sweden where the management of large carnivores is devolved to regional authorities and stakeholder-based Wildlife Management Delegations (WMDs), attempts to regionally solve conflicts are often overthrown by the national environmental protection agency or through court cases initiated by the environmental movement. Hence, compromises that potentially could solve conflicts are undermined. The analysis shows that while carnivore governance in both countries are founded on decentralized management authority at the regional level, local actors struggle for their views, experiences and knowledge to be acknowledged and counted as valid in the management process. While the decentralized management model opens for inclusion of different knowledge systems, this system has yet to acknowledge the challenges of knowledge being dismissed or marginalized across governance levels and scales

Orientation relationship between b-Si3N4 and Si in multicrystalline silicon ingots for PV applications

β-Si3N4 particles are thought to be nucleation sites for silicon in multicrystalline silicon (mc-Si) ingots for PV applications. The orientation relationship (OR) between Si and β-Si3N4 has been investigated by transmission electron microscopy (TEM). The following OR was found by analyzing diffraction patterns from a site specific sample prepared by focused ion beam (FIB) The β-Si3N4 particle was identified as a likely nucleation site based on the grain boundaries (GB) extending from it. It was shown that these GBs were Σ3 boundaries. The nucleation process was discussed as a source for formation of twins in mc-Si