Biology subjects

Finlay, J.

Publications and source records attributed to Finlay, J..

3 recordsLinked to original sources

bioRxiv2025

Predicting lead hotspots in urban stormwater ponds across the Twin Cities Metro

Stormwater ponds play an important role in urban food webs. Critically these same ponds could also serve as pollution hotspots since stormwater ponds can act as local concentrators of urban runoff. One such contaminant of concern is lead, which remains a significant issue for human and ecosystem health in the United States despite regulatory bans on its use in paint and gasoline imposed in the 1970s. Despite high levels of lead in some urban stormwater, little is known about the distribution of lead in urban aquatic ecosystems. Therefore, we characterized lead within the sediment, water column, and surrounding soil of stormwater ponds across the Minneapolis-Saint Paul Metro Area. We hypothesized that lead would be highest in ponds that receive runoff from landscapes with older construction (i.e., legacy leaded paint and gasoline), have high traffic volume (i.e., legacy leaded gasoline), and areas with low impervious surface cover (i.e., increased mobilization of contaminated soil). Moreover, we hypothesized that stormwater ponds capture lead within sediments, with more dissolved lead at the bottom of the water column, where it would interact with lead containing sediments. Across ponds, we found that age of parcel development where the pond was located was the strongest predictor of surface sediment lead content. Within pond sediments, we found that lead concentrations increased with depth below the sediment surface, which is unsurprising since depth is likely correlated with time. The strongest predictor of surface water lead concentration was the strength of pond stratification, while the strongest predictor of bottom water lead concentration was pond duckweed cover and water conductivity. Water column oxygen concentrations varied across ponds yet were not important in determining dissolved lead within the water column. Importantly, lead within pond water remained quite low despite elevated sediment lead levels. These findings confirm that stormwater ponds can act as one source of environmental lead remediation by capturing lead within sediments under a wide range of environmental conditions. Our results suggest relatively low lead release from ponds to downstream areas, indicating that ponds generally serve as sinks, not sources within the urban lead cycle.

ecology↗

bioRxiv2023

Intracranial tumors elicit systemic sympathetic hyperactivity that limits immunotherapeutic responses

Intracranial tumors present unique challenges for immunotherapy. These can include both local and systemic modes of immune suppression whose mechanistic underpinnings are incompletely understood. Here, we reveal that tumors harbored intracranially elicit systemic increases to circulating catecholamine levels, with the resultant chronic sympathetic hyperactivity driving T cell dysfunction and limiting immunotherapeutic success. Conversely, treatment with {beta}-adrenergic blockade increases NF-{kappa}B activity in immune cells, restores T cell polyfunctionality, modifies the tumor microenvironment, and licenses immune-based therapies in murine models of glioblastoma (GBM) to extend survival. Extended survival is also observed in GBM patients having received {beta}-adrenergic blockade, as well as in patients with melanoma and lung cancer brain metastases who received {beta}-blockade alongside concomitant immune checkpoint inhibition. While {beta}-blockade also impacts outcomes in the setting of extracranial disease, the benefits are especially pronounced in patients harboring intracranial disease burdens. These data suggest that sympathetic hyperactivity facilitates systemic immune dysfunction in the setting of intracranial tumors, specifically and advance a role for {beta}-adrenergic blockade in licensing immunotherapeutic responses within the intracranial compartment.

immunology↗

bioRxiv2021

Rapid blood acid-base regulation by European sea bass (Dicentrarchus labrax) in response to sudden exposure to high environmental CO2

Fish in coastal ecosystems can be exposed to acute variations in CO2 that can approach 1 kPa CO2 (10,000 atm). Coping with this environmental challenge will depend on the ability to rapidly compensate the internal acid-base disturbance caused by sudden exposure to high environmental CO2 (blood and tissue acidosis); however, studies about the speed of acid-base regulatory responses in marine fish are scarce. We observed that upon exposure to ~1 kPa CO2, European sea bass (Dicentrarchus labrax) completely regulate erythrocyte intracellular pH within ~40 minutes, thus restoring haemoglobin-O2 affinity to pre-exposure levels. Moreover, blood pH returned to normal levels within ~2 hours, which is one of the fastest acid-base recoveries documented in any fish. This was achieved via a large upregulation of net acid excretion and accumulation of HCO3- in blood, which increased from ~4 to ~22 mM. While the abundance and intracellular localisation of gill Na+/K+-ATPase (NKA) and Na+/H+ exchanger 3 (NHE3) remained unchanged, the apical surface area of acid-excreting gill ionocytes doubled. This constitutes a novel mechanism for rapidly increasing acid excretion during sudden blood acidosis. Rapid acid-base regulation was completely prevented when the same high CO2 exposure occurred in seawater with experimentally reduced HCO3- and pH, likely because reduced environmental pH inhibited gill H+ excretion via NHE3. The rapid and robust acid-base regulatory responses identified will enable European sea bass to maintain physiological performance during large and sudden CO2 fluctuations that naturally occur in coastal environments. Summary statementEuropean sea bass exposed to 1 kPa (10,000 atm) CO2 regulate blood and red cell pH within 2 hours and 40 minutes, respectively, protecting O2 transport capacity, via enhanced gill acid excretion.

physiology↗