Biology subjects

LaRue, M.

Publications and source records attributed to LaRue, M..

5 recordsLinked to original sources

bioRxiv2025

Historical remote sensing highlights long-term persistence of Emperor Penguin (Aptenodytes forsteri) colonies

Historical remote sensing imagery, including digital Landsat and analog Keyhole have potential to inform Antarctic conservation by providing insights into habitat and population dynamics. A case in point is that their long temporal range, extending as far back as the 1960s, offers an unparalleled look into the distribution of Emperor Penguin (Aptenodytes forsteri) colonies and their habitat. Here we demonstrate that Keyhole and Landsat sensors are capable of detecting presence and long-term change in penguin guano on sea-ice despite challenging environmental conditions. For 18 of the 66 known emperor penguin colonies, we confirmed their presence in images that predate earliest published records. We further used dense time series from 1960s to 2024 of the Cape Washington colony to exemplify change in guano area over time - but found little variation in guano area. We show that the guano area undergoes two distinct stages during a breeding season (a stable and clustered early stage, and a diffused and widespread late stage). We correlated guano area with penguin colony size and found that guano area correlates with colony size (Spearmans {rho} = 0.59, p-value = 0.017). Taken together, our results suggest long term resilience of penguin colonies in face of global change, and highlight that the use of historical remote sensing imagery across the Antarctic can inform conservation efforts and benefit the ongoing historical studies of penguin colony dynamics. We highlight the benefit of remote sensing for documenting otherwise inaccessible colonies and for quantifying and understanding historical colony dynamics.

ecology↗

bioRxiv2023

Controlled experiment finds no detectable citation bump from Twitter promotion

Multiple studies across a variety of scientific disciplines have shown that the number of times that a paper is shared on Twitter (now called X) is correlated with the number of citations that paper receives. However, these studies were not designed to answer whether tweeting about scientific papers causes an increase in citations, or whether they were simply highlighting that some papers have higher relevance, importance or quality and are therefore both tweeted about more and cited more. The authors of this study are leading science communicators on Twitter from several life science disciplines, with substantially higher follower counts than the average scientist, making us uniquely placed to address this question. We conducted a three-year-long controlled experiment, randomly selecting five articles published in the same month and journal, and randomly tweeting one while retaining the others as controls. This process was repeated for 10 articles from each of 11 journals, recording Altmetric scores, number of tweets, and citation counts before and after tweeting. Randomization tests revealed that tweeted articles were downloaded 2.6-3.9 times more often than controls immediately after tweeting, and retained significantly higher Altmetric scores (+81%) and number of tweets (+105%) three years after tweeting. However, while some tweeted papers were cited more than their respective control papers published in the same journal and month, the overall increase in citation counts after three years (+7% for Web of Science and +12% for Google Scholar) was not statistically significant (p > 0.15). Therefore while discussing science on social media has many professional and societal benefits (and has been a lot of fun), increasing the citation rate of a scientists papers is likely not among them.

scientific communication and education↗

bioRxiv2023

Urban living can rescue Darwin's finches from the lethal effects of invasive vampire flies

Human activity changes multiple factors in the environment, which can have additive or neutralizing effects on organisms. However, few studies have explored the causal effects of multiple anthropogenic factors, such as urbanization and invasive species, on animals, and the mechanisms that mediate these interactions. This study examines the influence of urbanization on the detrimental effect of invasive avian vampire flies (Philornis downsi) on endemic Darwins finches in the Galapagos Islands. We experimentally manipulated nest fly abundance in an urban and non-urban area and then characterized nestling health, survival, diet, and gene expression patterns related to host defense. Survival of fumigated nestlings from urban and non-urban nests did not differ significantly. However, sham-fumigated, non-urban nestlings lost more blood and few nestlings survived compared to urban nestlings. Stable isotopic values ({delta}15N) from urban nestling feces were higher than non-urban nestlings, suggesting that urban nestlings are consuming more protein. {delta}15N values correlated negatively with parasite abundance, which suggests that diet might influence host defenses (e.g., tolerance and resistance). Parasitized urban nestlings differentially expressed genes within pathways associated with red blood cell production (tolerance) and pro-inflammatory response (innate immunological resistance), compared to sham-fumigated non-urban nestlings. In contrast, sham-fumigated non-urban nestlings differentially expressed genes within pathways associated with immunoglobulin production (adaptive immunological resistance). Our results suggest that urban nestlings are investing more in pro-inflammatory responses to resist parasites, but also recovering more blood cells to tolerate blood loss. Although non-urban nestlings are mounting an adaptive immune response, it is likely a last effort by the immune system rather than an effective defense against avian vampire flies since few nestlings survived.

ecology↗

bioRxiv2022

Route of mRNA vaccination modulates the establishment of pulmonary resident memory CD8 and CD4 T cells

Respiratory tract resident memory T cells (Trm), typically generated by local vaccination or infection, can accelerate control of pulmonary infections that evade neutralizing antibody. It is unknown whether mRNA vaccination establishes respiratory Trm. We generated a self-amplifying mRNA vaccine encoding the influenza A virus nucleoprotein that is encapsulated in modified dendron-based nanoparticles. Here we report how routes of immunization in mice, including contralateral versus ipsilateral intramuscular boosts, or intravenous and intranasal routes, influence influenza-specific cell-mediated and humoral immunity. Parabiotic surgeries revealed that intramuscular immunization was sufficient to establish CD8 Trm in lung and draining lymph node. Contralateral, compared to ipsilateral, intramuscular boosting broadened the distribution of LN Trm and T follicular helper cells, but slightly diminished resulting levels of serum antibody. Intranasal mRNA delivery established modest circulating CD8 and CD4 T cell memory, but augmented distribution to the respiratory mucosa. Of note, combining intramuscular immunizations with an intranasal mRNA boost achieved high levels of both circulating T cell memory and lung Trm. Thus, routes of mRNA vaccination influence humoral and cell-mediated immunity, and intramuscular prime-boosting establishes lung Trm that can be further enhanced by an additional intranasal immunization.

immunology↗

bioRxiv2020

Reducing error and increasing reliability of wildlife counts from citizen science surveys: counting Weddell Seals in the Ross Sea from satellite images

Citizen science programs can be effective at collecting information at large temporal and spatial scales. However, sampling bias is a concern in citizen science datasets and can lead to unreliable estimates. We address this issue with a novel approach in a first-of-its-kind citizen science survey of Weddell seals for the entire coast of Antarctica. Our citizen scientists inspected very high-resolution satellite images to tag any presumptive seals hauled out on the fast ice during the pupping period. To assess and reduce the error in counts in term of bias and other factors, we ranked surveyors on how well they agreed with each other in tagging a particular feature (presumptive seal), and then ranked these features based on the ranking of surveyors placing tags on them. We assumed that features with higher rankings, as determined by "the crowd wisdom," were likely to be seals. By comparing citizen science feature ranks with an experts determination, we found that non-seal features were often highly ranked. Conversely, some seals were ranked low or not tagged at all. Ranking surveyors relative to their peers was not a reliable means to filter out erroneous or missed tags; therefore, we developed an effective correction factor for both sources of error by comparing surveyors tags to those by the expert. Furthermore, counts may underestimate true abundance due to seals not being present on the ice when the image was taken. Based on available on-the-ground haul-out location counts in Erebus Bay, the Ross Sea, we were able to correct for the proportion of seals not detected through satellite images after accounting for year, time-of-day, location (islet vs. mainland locations), and satellite sensor effects. We show that a prospective model performed well at estimating seal abundances at appropriate spatial scales, providing a suitable methodology for continent-wide Weddell Seal population estimates.

ecology↗