ARTICLE Kinetic Modeling of Phototrophic Biofilms: The PHOBIA Model

ABSTRACT: A kinetic model for mixed phototrophic biofilms is introduced, which focuses on the interactions between photoautotrophic, heterotrophic, and chemoautotrophic (nitrifying) functional microbial groups. Biofilmspecific phenomena are taken into account, such as extracellular polymeric substances (EPS) production by phototrophs as well as gradients of substrates and light in the biofilm. Acid-base equilibria, in particular carbon speciation, are explicitly accounted for, allowing for the determination of pH profiles across the biofilm. Further to previous models reported in literature, the PHOBIA model combines a number of kinetic mechanisms specific to phototrophic microbial communities, such as internal polyglucose storage under dynamic light conditions, phototrophic growth in the darkness using internally stored reserves, photoadaptation and photoinhibition, preference for ammonia over nitrate as N-source and the ability to utilize bicarbonate as a carbon source in the absence of CO 2 . The sensitivity of the PHOBIA model to a number of key parameters is analyzed. An example on the potential use of phototrophic biofilms in wastewater polishing is discussed, where their performance is compared with conventional algal ponds. The PHOBIA model is presented in a manner that is compatible with other reference models in the area of water treatment. Its current version forms a theoretical base which is readily extendable once further experimental observations become available

The Influence of IL-10 and TNFα on Chondrogenesis of Human Mesenchymal Stromal Cells in Three-Dimensional Cultures

Chondrogenic differentiated mesenchymal stromal cells (MSCs) are a promising cell source for articular cartilage repair. This study was undertaken to determine the effectiveness of two three-dimensional (3D) culture systems for chondrogenic MSC differentiation in comparison to primary chondrocytes and to assess the effect of Interleukin (IL)-10 and Tumor Necrosis Factor (TNF)α on chondrogenesis by MSCs in 3D high-density (H-D) culture. MSCs were isolated from femur spongiosa, characterized using a set of typical markers and introduced in scaffold-free H-D cultures or non-woven polyglycolic acid (PGA) scaffolds for chondrogenic differentiation. H-D cultures were stimulated with recombinant IL-10, TNFα, TNFα + IL-10 or remained untreated. Gene and protein expression of type II collagen, aggrecan, sox9 and TNFα were examined. MSCs expressed typical cell surface markers and revealed multipotency. Chondrogenic differentiated cells expressed cartilage-specific markers in both culture systems but to a lower extent when compared with articular chondrocytes. Chondrogenesis was more pronounced in PGA compared with H-D culture. IL-10 and/or TNFα did not impair the chondrogenic differentiation of MSCs. Moreover, in most of the investigated samples, despite not reaching significance level, IL-10 had a stimulatory effect on the type II collagen, aggrecan and TNFα expression when compared with the respective controls

Site Resource Inventories – a Missing Link in the Circular City's Information Flow

A circular city builds upon the principles of circular economy, which key concepts of reduce, reuse, recycle, and recover lead to a coupling of resources: products and by-products of one production process become the input of another one, often in local vicinity. However, sources, types and available quantities of underutilised resources in cities are currently not well documented. Therefore, there is a missing link in the information flow of the circular city between potential users and site-specific data. To close this gap, this study introduces the concept of a site resource inventory in conjunction with a new information model that can manage the data needed for advancing the circular city. A core taxonomy of terms is established as the foundation for the information model: the circular economy is defined as a network of circular economy entities which are regarded as black boxes and connected by their material and energy inputs and outputs. This study proposes a site resource inventory, which is a collection of infrastructural and building-specific parameters that assess the suitability of urban sites for a specific circular economy entity. An information model is developed to manage the data that allows the entities to effectively organise the allocation and use of resources within the circular city and its material and energy flows. The application of this information model was demonstrated by comparing the demand and availability of required alternative resources (e.g. greywater) at a hypothetical site comprising a commercial aquaponic facility (synergistic coupling of fish and vegetables production) and a residential building. For the implementation of the information model a proposal is made which uses the publicly available geodata infrastructure of OpenStreetMap and adopts its tag system to operationalise the integration of circular economy data by introducing new tags. A site resource inventory has the potential to bring together information needs and it is thus intended to support companies when making their business location decisions or to support local authorities in the planning process

Mesenchymal stromal cells of myelodysplastic syndrome and acute myeloid leukemia patients have distinct genetic abnormalities compared with leukemic blasts

Mesenchymal stromal cells (MSCs) are an essential cell type of the hematopoietic microenvironment. Concerns have been raised about the possibility that MSCs undergo malignant transformation. Several studies, including one from our own group, have shown the presence of cytogenetic abnormalities in MSCs from leukemia patients. The aim of the present study was to compare genetic aberrations in hematopoietic cells (HCs) and MSCs of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) patients. Cytogenetic aberrations were detected in HCs from 25 of 51 AML patients (49%) and 16 of 43 MDS patients (37%). Mutations of the FLT3 and NPM1 genes were detected in leukemic blasts in 12 (23%) and 8 (16%) AML patients, respectively. Chromosomal aberrations in MSCs were detected in 15 of 94 MDS/AML patients (16%). No chromosomal abnormalities were identified in MSCs of 36 healthy subjects. We demonstrate herein that MSCs have distinct genetic abnormalities compared with leukemic blasts. We also analyzed the main characteristics of patients with MSCs carrying chromosomal aberrations. In view of these data, the genetic alterations in MSCs may constitute a particular mechanism of leukemogenesis