Biology subjects

Coates, K.

Publications and source records attributed to Coates, K..

4 recordsLinked to original sources

bioRxiv2026

Examining urban weed response to elevated salt levels

Stressors from the urban environment cause adverse effects on city-dwelling organisms. While there is evidence that some species are adapting to urban stressors, such as the urban heat island and impervious surfaces, other stressors such as road salt are less studied. We investigated whether plants are adapting to elevated salt concentrations with two common garden experiments using three common weed species: Veronica arvensis, Stellaria media, and Lamium purpureum. We collected plants from parks around Baltimore, MD, USA, collecting plant maternal lineages from roadside soils (i.e. higher soil salinity) and inner park soils (i.e. lower soil salinity). We hypothesized that roadside lineages would tolerate salt treatment better than park lineages. In our germination experiment on wild-collected seeds, we observed a non-significant trend where the germination rate of roadside L. purpureum lineages was reduced less by salt treatment than for park genetic lineages, while S. media had similar declines between groups. In our greenhouse experiment on the F1 generation, roadside V. arvensis lineages displayed a less adverse reaction to salt treatment than park V. arvensis lineages. L. purpureum did not display this difference, but roadside lineages of both species exhibited less tissue damage overall. The results of our experiments were likely influenced by the maternal environment, and work on F2 generations is required to confirm them. Our findings show some support for urban salt tolerance adaptation, and point to the heterogeneity of the urban environment and the complexity of plant reactions to salinity.

ecology↗

bioRxiv2026

Leg blood flow and muscle oxygenation are reduced when exercising with loads >=40% 1RM compared to loads <=30% 1RM due to increases in contraction induced intramuscular pressure

The critical occluding tension (COT) is the load at which contraction-induced increases in intramuscular pressure (IMP) collapse intramuscular vasculature and impair oxygen delivery. For knee extension resistance exercise, the COT occurs at ~30-40% 1RM, yet few studies have measured IMP alongside convective oxygen delivery. This study examined the interaction between IMP, leg blood flow, and muscle oxygenation during resistance exercise. Twelve participants completed knee extension bouts across a range of loads while vastus lateralis IMP, femoral blood flow (Doppler), blood pressure, muscle oxygenation (NIRS), and electromyography (EMG) were recorded. Mean IMP increased alongside relative load (20% 1RM=19.1(9.4) mmHg; 30% 1RM=22.4(10.4) mmHg; 40% 1RM=27.0(8.7) mmHg; 50% 1RM=31.5(11.5) mmHg; 60% 1RM=41.14(13.8) mmHg; p<0.05). Leg blood flow scaled to rest was similar between 20% and 30% 1RM (p=0.13), 40%, 50%, and 60% 1RM (p>0.05), but different between the 20-30% 1RM and 40-60% 1RM groupings (p<0.05) (20% 1RM=2.6(1.4) times rest; 30% 1RM=1.8(0.5) fold of rest; 40% 1RM=1.4(0.6) fold of rest; 50% 1RM=1.1(0.4) fold of rest; 60% 1RM=1.1(0.5) fold of rest). Muscle oxygenation was lower at 40%, 50%, and 60% 1RM compared to 20% and 30% 1RM (p<0.05). Thus, at [≤]30% 1RM exercising blood flow increased well above rest, indicating preserved microvascular perfusion, whereas at [≥]40% 1RM the rise in IMP was sufficient to impair perfusion and limit blood flow increases. Exercise at or above the COT restricts convective oxygen delivery due to contraction-induced increases in IMP.

physiology↗

bioRxiv2022

I Am A Scientist: Overcoming implicit bias in STEM through explicit representations of diversity in lectures

The lack of diversity in Science, Technology, Engineering and Mathematics (STEM) is a significant issue for the sector. Many organisations and educators have identified lack of representation of historically marginalised groups within teaching materials as a potential barrier to students feeling that a STEM career is something that they can aspire to. A key barrier to addressing the issue is providing accessible and effective evidence-based approaches for educators to implement. In this study, we explore the potential for adapting presentation slides within lectures to humanise the scientists involved, presenting their full names and photographs alongside a Harvard style reference. We adopt a questionnaire based methodology, and survey 161 undergraduates and postgraduates at a UK civic university. We first establish that students project implicit biases onto a hypothetical reference, with over 50% of students assuming the scientist was male and Western. We then explore what students think of the humanised slide design, concluding that most students see it as good pedagogical practice, with some students positively changing their perceptions about diversity in science. We were unable to compare responses by ethnicity, but find evidence that female and non-binary students are more likely to see this as good pedagogical practice, perhaps reflecting white male fragility in being exposed to initiatives designed to highlight diversity. We conclude that humanised powerpoint slides are a potentially effective tool to highlight diversity of scientists within existing research-led teaching, but highlight that this is only a small intervention that needs to sit alongside more substantive work to address the lack of diversity in STEM.

scientific communication and education↗

bioRxiv2019

Regulation of modulatory cell activity across olfactory structures in Drosophila melanogaster

All centralized nervous systems possess modulatory neurons that arborize broadly across multiple brain regions. Such modulatory systems are critical for proper sensory, motor, and cognitive processing. How single modulatory neurons integrate into circuits within their target destination remains largely unexplored due to difficulties in both labeling individual cells and imaging across distal parts of the CNS. Here, we take advantage of an identified modulatory neuron in Drosophila that arborizes in multiple olfactory neuropils. We demonstrate that this serotonergic neuron has opposing odor responses in its neurites of the antennal lobe and lateral horn, first and second order olfactory neuropils respectively. Specifically, processes of this neuron in the antennal lobe have responses that are inhibitory and odor-independent, while lateral horn responses are excitatory and odor-specific. The results show that widespread modulatory neurons may not function purely as integrate-and-fire cells, but rather their transmitter release is locally regulated based on neuropil. As nearly all vertebrate and invertebrate neurons are subject to synaptic inputs along their dendro-axonic axis, it is likely that our findings generalize across phylogeny and other broadly-projecting modulatory systems.\n\nSignificanceThe centrifugal innervation of neuronal circuits is ubiquitous across centralized nervous systems. Such inputs often arise from modulatory neurons that arborize broadly throughout the brain. How information is integrated in such cells and how release from their distant terminals is regulated remains largely unknown. We show that a serotonergic neuron that innervates multiple stages of odor processing in Drosophila has distinct activity throughout its neurites, including opposite polarity responses in first and second order olfactory neuropils. Disparate activity arises from local interactions within each target region. Our results show that such neurons exhibit dendritic computation rather than somatic integration alone, and that examining local interactions at release sites is critical for understanding centrifugal innervation.

neuroscience↗