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Summary: Macrophages are key innate immune cells involved in multiple biological processes, including peripheral nerve regeneration. Here, we describe a protocol for the adoptive cell transfer of bone-marrow-derived macrophages (BMDMs) following sciatic nerve crush injury (SNCI). This procedure involves isolating BMDMs from a donor mouse, potentially manipulating them ex vivo, and reintroducing them into an animal following SNCI. Preclinical studies show that BMDMs can infiltrate injured nerves and impact functional recovery, potentially providing a novel therapy for nerve injuries.For complete details on the use and execution of this protocol, please refer to Jha et al.1 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

Emerging evidence suggests that zooplankton production is affected by physiological and nutritional constraints due to climate change and eutrophication, which in turn could have broad implications for food-web dynamics and fisheries production. In this study, we developed a resource-based zooplankton production dynamics model that causally links freshwater cladoceran and copepod daily production-to-biomass (P/B) ratios with water temperature, phytoplankton biomass and community composition, and zooplankton feeding selectivity. This model was used to evaluate constraints on zooplankton growth under four hypothetical scenarios: involving natural plankton community seasonal succession; lake fertilization to enhance fisheries production; eutrophication; and climatic warming. Our novel modeling approach predicts zooplankton production is strongly dependent on seasonal variation in resource availability and quality, which results in more complex zooplankton dynamics than predicted by simpler temperature-dependent models. For mesotrophic and hypereutrophic lakes, our study suggests that the ultimate control over zooplankton P/B ratios shifts from physiological control during colder periods to strong resource control during warmer periods. Our resource-based model provides important insights into the nature of biophysical control of zooplankton under a changing climate that has crucial implications for food web energy transfer and fisheries production. De nouvelles observations semblent indiquer que des contraintes physiologiques et nutritives decoulant des changements climatiques et de l'eutrophisation ont une incidence sur la production de zooplancton, ce qui pourrait avoir de vastes repercussions sur la dynamique des reseaux trophiques et la production des peches. Nous avons developpe un modele de dynamique de la production de zooplancton base sur les ressources qui relie causalement les rapports quotidiens de la production et de la biomasse (P/B) de cladoceres et de copepodes d'eau douce a la temperature de l'eau, la biomasse et la composition de la communaute du phytoplancton et la selectivite de l'alimentation du zooplancton. Le modele est utilise pour evaluer les contraintes a la croissance du zooplancton dans quatre scenarios hypothetiques, a savoir : une succession saisonniere naturelle de la communaute de plancton, la fertilisation du lac pour accroitre la production des peches, l'eutrophisation et le rechauffement climatique. Notre nouvelle approche de modelisation predit que la production de zooplancton depend fortement des variations saisonnieres de la disponibilite et de la qualite des ressources, ce qui se traduit par une dynamique du zooplancton plus complexe que ce que predisent les modeles plus simples dependants de la temperature. Pour les lacs mesotrophes et hypereutrophes, l'etude indiquerait que les rapports P/B du zooplancton sont ultimement controles par la physiologie durant les periodes plus froides et par les ressources durant les periodes plus chaudes. Notre modele base sur les ressources fournit d'importants renseignements sur la nature du controle biophysique du zooplancton dans des conditions de climat changeant qui a d'importantes repercussions sur les transferts energetiques dans les reseaux trophiques et la production des peches. [Traduit par la Redaction], Introduction Zooplankton represent a biochemical filter in lakes wherein primary producer organic matter is converted to animal matter. Due to the large disparity in phytoplankton and zooplankton biochemical composition, energetic [...]

This article discusses the importance of accurate scientific communication through press releases and the potential consequences of disseminating inaccurate information. The authors address a specific press release about the water clarity of Lake Tahoe, which incorrectly attributed the improvement in clarity to zooplankton. They argue that the data and peer-reviewed scientific literature contradict this claim and suggest that other factors, such as sediment inputs and climate dynamics, are responsible for the changes in clarity. The authors also provide recommendations for improving the communication of scientific information through press releases, emphasizing the need for peer review and open data sharing. [Extracted from the article]

Wind is a critical driving force in hydrodynamic and water quality modeling of large shallow lakes, and is characterized by the wind drag coefficient Cd, representing the momentum transfer at the air‐water interface. Contemporary empirical formulae for Cd estimation were derived over oceans and some of which are solely wind velocity U10 dependent. These formulae were previously found to be inadequate in inland lake models often resulting in the water velocity underestimation. To address this problem, a physical scale experiment was designed, in which Cd was measured using a wind profile and eddy covariance methodology. A new wind‐induced wave‐dependent Cd parameterization was also established and validated in two lake studies. The driving force was modified by the wave‐dependent Cd formula in a hydrodynamic model of the shallow Upper Klamath Lake (UKL), OR, USA. The experimental Cd was negatively correlated to the wind velocity up until the critical U10 = 1.6 m s−1 which was 1.0~3.1 times previous empirical extrapolations at light winds. The variation partitioning results showed that wave parameters contributed to more than 30% of Cd variation combined with wind parameters. The modified wind stress field was spatially heterogeneous and the modeled water velocity was closer to the observations at two sites. Significant main circulation and outer bank circulation were modeled accompanied by higher surface vorticity, compared to the original UKL model. Overall, the wave‐dependent Cd formula provided an improvement of the surface flow field in the UKL model and will improve the management of the lake ecosystems. Plain Language Summary: As a critical driving force in large shallow lakes, wind parameterization is of great importance for accurate hydrodynamic modeling. Previous wind‐dependent wind drag formulae over oceans usually generate large underestimates of water velocity in lakes. We thus propose a new wave‐dependent Cd parameterization based on an experimental study to improve the Cd parameterization in lakes. The Cd measurements were compared and confirmed by two typical methodologies of wind profile and eddy covariance. The newly derived wave‐dependent Cd parameterization was validated in two lake studies and adapted to a hydrodynamic model of the Upper Klamath Lake, OR, USA. Results showed an improved representation of the wind stress field, surface water velocity, and surface circulation. Our work should therefore be useful when using mechanistic models to manage hydrodynamics and water quality in large shallow lakes. Key Points: A wave‐dependent Cd formula was developed based on an experimental study, indicating a negative correlation of Cd with U10 at light windsSpatial heterogeneity of the wind stress field and surface circulation was identified in lake hydrodynamic modelingThe adaptation of Cd parameterization in a hydrodynamic model was improved through the wave‐dependent Cd formula [ABSTRACT FROM AUTHOR]

There is growing recognition of the importance of food quality over quantity for aquatic consumers. In streams and rivers, most previous studies considered this primarily in terms of the quality of terrestrial leaf litter and importance of microbial conditioning. However, many recent studies suggest that algae are a more nutritional food source for riverine consumers than leaf litter. To date, few studies have quantified longitudinal shifts in the nutritional quality of basal food resources in river ecosystems and how these may affect consumers.We conducted a field investigation in a subalpine river ecosystem in Austria to investigate longitudinal variations in diet quality of basal food sources (submerged leaves and periphyton) and diet source dependence of stream consumers (invertebrate grazers, shredders, filterers and predators, and fish). Fatty acid (FA) profiles of basal food sources and their consumers were measured.Our results indicate systematic differences between the FA profiles of terrestrial leaves and aquatic biota, that is periphyton, invertebrates and fish. Submerged leaves contained very low proportions of long‐chain polyunsaturated fatty acids (LC‐PUFAs), which were conversely rich in aquatic biota. While the FA composition of submerged leaves remained similar among sites, the LC‐PUFAs of periphyton increased longitudinally, which was associated with increasing nutrients from upstream to downstream.Longitudinal variations in periphyton LC‐PUFAs were reflected in the LC‐PUFAs of invertebrate grazers and shredders, and further tracked by invertebrate predators and fish. However, brown trout Salmo trutta contained a large proportion of docosahexaenoic acid (DHA, 22:6ω3), a LC‐PUFA almost entirely missing in basal sources and invertebrates. The fish accumulated eicosapentaenoic acid (EPA, 20:5ω3) from invertebrate prey and may use this FA to synthesize DHA.Our results provide a nutritional perspective for river food web studies, emphasizing the importance of algal resources to consumer somatic growth and the need to account for the longitudinal shifts in the quality of these basal resources. [ABSTRACT FROM AUTHOR]