Biology subjects

Rusch, G.

Publications and source records attributed to Rusch, G..

3 recordsLinked to original sources

bioRxiv2026

Where conservation and restoration matter most: sensitivity-based prioritization of connected forest

Achieving global conservation and restoration targets requires knowing not only how much land to conserve and restore, but also where such actions will have the greatest ecological effect. Conservation and, in particular, restoration priorities are often inferred from habitat condition, opportunity, or broad ecological value, yet these criteria do not necessarily identify where local changes generate the largest landscape-scale consequences. Building on sensitivity-based conservation prioritization, we extend the approach to derive ecological loss and gain potential by differentiating a persistence-relevant connectivity metric with respect to local habitat condition. Sensitivity identifies areas where local degradation or improvement would most strongly affect connected habitat at the landscape scale. Combining sensitivity with current condition distinguishes high loss potential, where degradation would have large ecological consequences, from high gain potential, where ecological improvement could generate large benefits. Applying the framework to national forest-naturalness data in Norway, we show that loss and gain potential are spatially related but far from redundant, and that gain potential is not simply concentrated in the most degraded forests. Both high-loss and high-gain areas were poorly represented within current protected areas, although loss potential was consistently better represented than gain potential. Extending sensitivity-based prioritization in this way provides a general and scalable means of linking local habitat-condition change to persistence-relevant landscape outcomes, while distinguishing the ecological potentials that can inform conservation and restoration decisions.

ecology↗

bioRxiv2024

Comparative Approaches for Quantification of Product Yield in a Model Recombinant Green Fluorescent Protein Expressed in E. coli

Process Analytical Technologies (PAT) are critical for efficient and automated bioprocessing; moreover, sensor and assay-driven automation will be necessary for the realization of Industry 4.0. Herein, we demonstrate methods for analyzing product yield from a pilot-scale bioreactor (300L) and conduct cross-method comparisons. We used a system of recombinant green fluorescent protein (GFPuv) expressed in Escherichia coli (E. coli), which is a simple, cost-effective model for evaluation at both laboratory and pilot scales. By comparing inline bioreactor measurements, plate reader assays, and a novel image analysis pipeline, we identify optimal harvest timelines and demonstrate the strengths and limitations of each technique. Results indicate peak cell density and GFPuv expression between 12.5h and 18h post-inoculation, with declining viability thereafter. Comparisons across techniques suggest that imaging methods may be more effective in capturing adverse outcomes, such as increased membrane permeability or cell death, which typically occur at later stages of operation. This integrated analysis offers actionable insights for optimizing biomanufacturing workflows and advances the development of scalable PAT applications, bridging the gap between laboratory research and industrial implementation.

biochemistry↗

bioRxiv2023

Simple Design for Membrane-Free Microphysiological Systems to Model the Blood-Tissue Barriers

Microphysiological systems (MPS) incorporate physiologically relevant microanatomy, mechanics, and cells to mimic tissue function. Reproducible and standardized in vitro models of tissue barriers, such as the blood-tissue interface (BTI), are critical for next-generation MPS applications in research and industry. Many models of the BTI are limited by the need for semipermeable membranes, use of homogenous cell populations, or 2D culture. These factors limit the relevant endothelial-epithelial contact and 3D transport, which would best mimic the BTI. Current models are also difficult to assemble, requiring precise alignment and layering of components. The work reported herein details the engineering of a BTI-on-a-chip (BTI Chip) that addresses current disadvantages by demonstrating a single layer, membrane-free design. Laminar flow profiles, photocurable hydrogel scaffolds, and human cell lines were used to construct a BTI Chip that juxtaposes an endothelium in direct contact with a 3D engineered tissue. A biomaterial composite, gelatin methacryloyl and 8-arm polyethylene glycol thiol, was used for in situ fabrication of a tissue structure within a Y-shaped microfluidic device. To produce the BTI, a laminar flow profile was achieved by flowing a photocurable precursor solution alongside phosphate buffered saline. Immediately after stopping flow, the scaffold underwent polymerization through a rapid exposure to UV light (<300 mJ{middle dot}cm-2). After scaffold formation, blood vessel endothelial cells were introduced and allowed to adhere directly to the 3D tissue scaffold, without barriers or phase guides. Fabrication of the BTI Chip was demonstrated in both an epithelial tissue model and blood-brain barrier (BBB) model. In the epithelial model, scaffolds were seeded with human dermal fibroblasts. For the BBB models, scaffolds were seeded with the immortalized glial cell line, SVGP12. The BTI Chip microanatomy was analyzed post facto by immunohistochemistry, showing the uniform production of a patent endothelium juxtaposed with a 3D engineered tissue. Fluorescent tracer molecules were used to characterize the permeability of the BTI Chip. The BTI Chips were challenged with an efflux pump inhibitor, cyclosporine A, to assess physiological function and endothelial cell activation. Operation of physiologically relevant BTI Chips and a novel means for high-throughput MPS generation was demonstrated, enabling future development for drug candidate screening and fundamental biological investigations. HIGHLIGHTSO_LIBarrier-type organs-on-a-chip are popular due to their mimicry of a variety of tissue constructs and interfaces. C_LIO_LITypical barrier-type organs-on-a-chip rely upon microperforated membranes and complex assembly, which limits both ease of fabrication the desired barrier performance. C_LIO_LIA membrane-free barrier-type organ-on-a-chip is designed, which uses simple Y-channel microfluidics and photopolymerization to form a precise "blood-tissue interface." C_LIO_LIFabrication of the membrane-free design can be easily parallelized and scaled-up. C_LI

bioengineering↗