Biology subjects

Kerr, M.

Publications and source records attributed to Kerr, M..

5 recordsLinked to original sources

bioRxiv2026

Two decades of Novel Ecosystems: Literature analysis of topics, trends and connectivity

1. As human-driven climate change and other anthropogenic forces produce widespread impacts on biodiversity and ecosystem functioning, many ecosystems are shifting into unprecedented, novel states. The Novel Ecosystem Concept (NEC), formalized in 2006, was developed as an alternative framework for managing "novel ecosystems", human-altered systems that are challenging to restore to their historical state. In the years since, the NEC has been proposed as a broader lens for ecosystem management under ongoing global change. 2. We evaluated how the uptake and potential of the NEC have been realized over time using a bibliometric and linguistic toolkit. Using bibliometric data from the Web of Science, we clustered 40,914 applied ecology papers published between 2006 and 2025 into twenty research topics based on language use. We quantified the volume of NEC research within each topic, rates of publication over time, and cross-topic connectivity proxied by citations. 3. We found NEC research in most of the topics of applied ecology, particularly invasion biology, ecosystem services, soil research and studies of freshwater, urban and marine systems. In contrast, several major conservation-focused topics, including protected areas, threatened species, and human-wildlife interactions, contained little research with an explicit link to novel ecosystems. Publication rates increased across all topics, although growth slowed over time. At the same time, NEC research became more focused into ecosystem-specific topics, especially marine ecosystems. NEC research across different topics was well-connected by citations, with papers more likely to cite each other when they used similar language. 4. Overall, the NEC does not appear to have expanded beyond its origins in restoration to become a broadly applied framework across conservation and ecosystem management. Instead, the concepts behind the NEC have been integrated into restoration and management frameworks grappling with climate and other anthropogenic change, while "novelty" is emerging as a powerful quantitative variable for measuring ecological change over space and time. Our results highlight the potential value of bibliometric and linguistic tools to deconstruct the ecological literature to inform what we can, or should, do to intervene for benefit of nature and people.

ecology↗

bioRxiv2025

Diverse ssRNA viruses associated with Karenia brevis harmful algal blooms in Southwest Florida

Harmful algal blooms (HABs) caused by the dinoflagellate Karenia brevis frequently occur in the eastern Gulf of Mexico, where they negatively impact the environment, human health, and economy. Very little is known about viruses associated with K. brevis blooms, although viral infection of other HAB-forming phytoplankton species can play an important role in bloom dynamics. We used viral metagenomics to identify viruses in 11 pooled seawater samples collected from Southwest Florida, USA in 2021 during a severe, spatiotemporally dynamic K. brevis bloom. Assembled viral genomes were similar to published genomes from the order Picornavirales, family Marnaviridae, and genera Sogarnavirus, Bacillarnavirus, and Marnarnavirus. Viruses from these groups infect bloom-forming diatoms (Chaetoceros sp. and Rhizosolenia setigera) and the raphidophyte Heterosigma akashiwo. We also recovered unclassified Riboviria genomes related to a Symbiodinium positive-sense ssRNA virus sequenced from coral dinoflagellate symbionts. Reverse-transcriptase PCR assays were performed to monitor the occurrence of seven representative virus genomes in these 2021 samples and 43 seawater samples collected during a subsequent, typical bloom between November 2022 and May 2023. Over half of the samples contained multiple viruses, and at least one viral genome was detected in 44 of 54 samples, collected across seasons and years, highlighting the ubiquity of these viruses in this region. Alpha diversity was highest in the summer months and positively correlated with K. brevis cell counts. Multiple regression revealed month and the presence of unclassified Riboviria sequences most similar to dinoflagellate viruses as significant predictors of K. brevis cellular abundance. ImportanceHarmful algal blooms caused by the dinoflagellate Karenia brevis negatively impact the tourism, fisheries, and public health sectors. Anticipated impacts of climate change, nutrient pollution, and ocean acidification may sustain and/or exacerbate K. brevis blooms in the future, underscoring the need for proactive monitoring, communication, and mitigation strategies. This study represents a pioneering effort in monitoring viruses associated with K. brevis blooms. The findings lay the groundwork for studying the effects of environmental drivers on K. brevis blooms and their associated viruses, as well as for exploring the roles of viruses in bloom dynamics and potential applications of viruses as biocontrol agents for K. brevis blooms. Furthermore, the comparison of viral dynamics relative to local and regional bloom dynamics in this study helps inform future monitoring and modeling needs.

microbiology↗

bioRxiv2022

Immune-responsive biodegradable scaffolds for enhancing neutrophil regeneration

Neutrophils are essential effector cells for mediating rapid host defense and their insufficiency arising from therapy-induced side-effects, termed neutropenia, can lead to immunodeficiency-associated complications. In autologous hematopoietic stem cell transplantation (HSCT), neutropenia is a complication that limits therapeutic efficacy. Here, we report the development and in vivo evaluation of an injectable, biodegradable hyaluronic acid (HA)-based scaffold, termed HA cryogel, with myeloid responsive degradation behavior. In mouse models of immune deficiency, we show that the infiltration of functional myeloid-lineage cells, specifically neutrophils, is essential to mediate HA cryogel degradation. Post-HSCT neutropenia in recipient mice delayed degradation of HA cryogels by up to 3 weeks. We harnessed the neutrophil-responsive degradation to sustain the release of granulocyte colony stimulating factor (G-CSF) from HA cryogels. Sustained release of G-CSF from HA cryogels enhanced post-HSCT neutrophil recovery, comparable to pegylated G-CSF, which, in turn, accelerated cryogel degradation. HA cryogels are a potential approach for enhancing neutrophils and concurrently assessing immune recovery in neutropenic hosts.

bioengineering↗

bioRxiv2021

Functional characterization of two variants in the mitochondrial topoisomerase gene TOP1MT that impact regulation of the mitochondrial genome

TOP1MT encodes a mitochondrial topoisomerase that is important for mtDNA regulation, and that is involved in mitochondrial replication, transcription and translation. Two variants predicted to affect TOP1MT function (V1 - R198C and V2 - V338L) were identified by exome sequencing of a newborn with hypertrophic cardiomyopathy. As no pathogenic TOP1MT variants had been confirmed previously, we characterized these variants for their ability to rescue several TOP1MT functions in knockout cells. Consistent with these TOP1MT variants contributing to the patient phenotype, comprehensive characterization suggests that both variants had impaired activity. Critically, neither variant was able to restore steady state levels of mitochondrial-encoded proteins, nor reduced oxidative phosphorylation when re-expressed in TOP1MT knockout cells. However, the two variants behaved differently in some respects. While the V1 variant was better at restoring transcript levels, the V2 variant was able to restore mtDNA copy number and replication. These findings suggest that the different TOP1MT variants affect distinct TOP1MT functions. Altogether, these findings begin to provide insight into the many roles that TOP1MT plays in the maintenance and expression of the mitochondrial genome, and how impairments in this important protein may lead to human pathology.

molecular biology↗

bioRxiv2018

Assessing the effect of hypoxia on cardiac metabolism using hyperpolarized 13C magnetic resonance spectroscopy

Abstract summaryHypoxia plays a role in many diseases and can have a wide range of effects on cardiac metabolism depending on the extent of the hypoxic insult. Non-invasive imaging methods could shed valuable light on the metabolic effects of hypoxia on the heart in vivo. Hyperpolarized carbon-13 magnetic resonance spectroscopy (HP 13C MRS) in particular is an exciting technique for imaging metabolism that could provide such information.\n\nThe aim of our work was, therefore, to establish whether hyperpolarized 13C MRS can be used to assess the in vivo response of cardiac metabolism to systemic acute and chronic hypoxic exposure. Groups of healthy male Wistar rats were exposed to either acute (30 minutes), one week or three weeks of hypoxia. In vivo MRS of hyperpolarized [1-13C]pyruvate was carried out along with assessments of physiological parameters and ejection fraction. No significant changes in heart rate, respiration rate, or ejection fraction were observed at any timepoint. Haematocrit was elevated after one week and three weeks of hypoxia.\n\nThirty minutes of hypoxia resulted in a significant reduction in pyruvate dehydrogenase (PDH) flux, whereas one or three weeks of hypoxia resulted in a PDH flux that was not different to normoxic animals. Conversion of hyperpolarized [1-13C]pyruvate into [1-13C]lactate was elevated following acute hypoxia, suggestive of enhanced anaerobic glycolysis. Elevated HP pyruvate to lactate conversion was also seen at the one-week timepoint, in concert with an increase in lactate dehydrogenase (LDH) expression. Following three weeks of hypoxic exposure, cardiac metabolism was comparable to that observed in normoxia.\n\nWe have successfully visualized of the effects of systemic hypoxia on cardiac metabolism using hyperpolarized 13C MRS, with differences observed following 30 minutes and 1 week of hypoxia. This demonstrates the potential of in vivo hyperpolarized 13C MRS data for assessing the cardiometabolic effects of hypoxia in disease.

physiology↗