The global warming phenomenon leads to elevated water temperatures in freshwater habitats, which in turn alters the motility responses of hemimetabolous macroinvertebrates. Ephemeroptera nymphs are highly active in different types of micro-habitats. Its movement complexity may shift with increasing temperature, but how this dynamic occurs has received little attention. Our work studies the two-dimensional and anisotropic movement behavior of Ephemeroptera nymphs (Baetidae and Leptophlebiidae) under an experimental setting that provides controlled induced thermal stress. Increasing temperatures could influence the movement patterns according to Fractal Dimension Index (FDI). FDI methods (radial, box-counting, and dilation) indicate the complexity of trajectories and directionality (anisotropy). Experiments were conducted in a controlled arena, recording the movement of nymphs under three thermal conditions: control (temperature from sampling sites), control +5°C and control +10°C, from several micro-habitats of rithronic streams. The results showed that thermal stress led to a decrease in FDI, suggesting a shift towards more directional and less complex movement patterns, i.e., an increase in anisotropy. This response was influenced by taxonomic family, with Baetidae showing greater sensitivity and a steeper drop in FDI compared to Leptophlebiidae. Micro-habitat complexity also played a crucial role; nymphs from structurally complex habitats (macrophytes and boulders) tended to maintain higher FDI values under stress, as opposed to those from simpler substrates (gravel and sand), which showed a sharper reduction in movement complexity. This indicates that habitat structural heterogeneity may mitigate the negative effects of heat stress on behavior. Positive correlations were found between habitat fractal dimensions and locomotor traits such as Mean speed and Total path length, suggesting that complex habitats may enhance nymph mobility. These findings support the use of fractal metrics as sensitive indicators of behavioral plasticity and complexity of animal movement under environmental stress.

Background Bone tissue engineering emerged as a practical approach to tackle the prosthetic industry limitations. Merging aspects from developmental biology, engineering and medicine with the aim to produce fully-functional bone tissue. Mesenchymal stem cells (MSCs) harbor the capability of self-renewal and specific lineage differentiation. Herein lies their potential for bone tissue engineering. Among MSCs, human dental pulp stem cells (hDPSCs) lodge higher proliferation rate, shorter doubling times, lower cellular senescence, and enhanced osteogenesis than hBM-SCs. In addition, these cells have ease in access and a subtle extraction procedure. Thus, harbouring fewer moral concerns than most MSCs available and embodying a promising cell source for BTE therapies able to replace hBM-MSCs. Interestingly, their study has been limited. Conversely, there is a need for their further study to harness their BTE true value, with special emphasis in the design of bioprocesses able to produce viable, homogenous bone constructs in a clinical scale. Methods Here, we study the in vitro osteogenic differentiation of hDPSCs encapsulated in alginate hydrogels under suspended culture in a novel and scalable perfusion bioreactor, establishing culture conditions; and compare it with three-dimensional (3D) static and fed-batch culture. Results hDPSC-based bone-like constructs produced in the novel system performed above the compared culture strategies, displaying higher alkaline phosphatase activity, more homogeneous, denser and functional bone constructs. In addition, cell constructs produced by the in-house designed system were richer in mature osteoblasts. Conclusion This study reports the development of a novel bioprocess able to produce hDPSC-alginate-based bone-like constructs to be used as bone fillers, while providing new insights into hDPSCs therapeutic potential and a system able to be transferred from the laboratory bench into medical facilities.

L-asparaginase is one of the world’s most in-demand industrial enzymes, mainly due to its therapeutic properties and its use in the food industry. Over the years studies have been conducted to improve its specific activity and reduce side effects, driving new discoveries that promise safer, more efficient, and cheaper drugs for consumers. However, heterologous protein modifications or expression continue to be a problem during production. Therefore, addressing bottlenecks when attempting to express modified and/or heterologous proteins using the rational design of heterologous expression systems with modified hosts could be a promising strategy to improve L-asparaginase production. Problems such as inadequate protein folding, metabolic load on host cells, codon usage bias, repetitive sequences affecting translation, heavy molecular weight and/or multi-membrane domains formation; need great attention during the development of “bio-better” proteins. In this article, we address the current molecular and metabolic strategies that have been developed to improve the heterologous expression of L-asparaginase.