Luke Calderaro

All Publications

• A nirK-cbb3 genomic region links SAR11 to nitrogen loss in the northern Benguela Upwelling System. Microbial genomics Morris, R. M., Mattes, T. E., Bubphamanee, K., Sadler, M. C., Calderaro, L. A., Karolewski, J., Casciotti, K. L., Mason, O. U. 2026; 12 (1)

  Abstract

  Denitrification leads to nitrogen loss from marine oxygen minimum zones. The complete metabolic pathway for denitrification reduces nitrate to dinitrogen gas in four sequential steps. Many facultatively anaerobic bacteria are capable of the initial step of nitrate reduction to nitrite. Far fewer contribute to nitrogen loss by reducing nitrite to nitric oxide, nitrous oxide or dinitrogen gas. We sequenced the genomes of 24 bacteria isolated from low-oxygen waters (23 µM) in the northern Benguela Upwelling System (nBUS) to identify species with the genetic potential for denitrification. Most isolates have the genetic potential for partial denitrification, including ten SAR11 strains with a genomic region that codes for a copper-containing nitrite reductase (NirK) and a high-affinity cbb3-type cytochrome c oxidase. Evidence that nBUS SAR11 have the potential to respire nitrite in low-dissolved-oxygen waters suggests that they could have a more direct role in marine nitrogen loss.

  View details for DOI 10.1099/mgen.0.001620

  View details for PubMedID 41553858

  View details for PubMedCentralID PMC12816887

• Environmental correlates of molluscan predator-prey body size in the northern Gulf of Mexico PALEOBIOLOGY Calderaro, L. A., Harnik, P. G., Rillo, M. C. 2024; 50 (1): 70-84

  View details for DOI 10.1017/pab.2023.22

  View details for Web of Science ID 001164711900012

• Can dogs serve as stress mediators to decrease salivary cortisol levels in a population of liberal arts college undergraduate students? EXPLORE-THE JOURNAL OF SCIENCE AND HEALING Jimenez, A., Calderaro, L., Clark, S., Elacqua, D., Hazen, E., Lam, V., Leightheiser, G. S. 2023; 19 (3): 283-289

  Abstract

  The steroid hormone cortisol can be used to measure physiological stress in humans. The hypothalamic-pituitary-adrenal (HPA) axis synthesizes cortisol, and a negative feedback cycle regulates cortisol depending on an individual's stress level and/or circadian rhythm. Chronic stress of college undergraduate students is associated with various adverse health effects, including anxiety and depression. Reports suggest that stress levels have risen dramatically in recent years, particularly among university students dealing with intense academic loads in addition to COVID-19 pandemic-related uncertainty. The increasing rate of mental illness on college campuses necessitates the study of mediators potentially capable of lowering stress, and thus cortisol levels. Research on mediation techniques and coping mechanisms have gained traction to address the concerning levels of stress, including the employment of human-animal interaction sessions on college campuses. In this study, human-canine interaction as a stress mediation strategy for undergraduate students was investigated. We measured salivary cortisol levels in 73 college undergraduate students during a 60-min interaction period with a dog to determine whether human-canine interactions are effective in lowering cortisol levels and potentially reducing chronic stress typical of undergraduate students. Our results indicate that a human-canine interaction for 60 min is an effective method for significantly reducing salivary cortisol and stress levels among undergraduate college students. These findings support the expansion of animal visitation programs on college campuses to help students manage stress.

  View details for DOI 10.1016/j.explore.2022.08.007

  View details for Web of Science ID 001052502800001

  View details for PubMedID 35989236