The Impact of COVID-19 on Bicycle-Related Injuries Managed at a Level 1 Major Trauma Center in London, United Kingdom.

Introduction The COVID-19 pandemic changed peoples' travel behaviors; an uptake in cycling was observed in the United Kingdom. The aim of this study was to assess the cycling-related orthopedic injuries presented to a major trauma center (MTC) before and during the COVID-19 pandemic. Method This retrospective observational single-center study analyzed referrals to the orthopedic department during a matched two-month period in 2019 and 2020. Data were collated on cycling-related injuries including demographic variables, mechanism of injury, anatomical area of injury, and the management of injury. The data were compared and statistical analysis was performed using the Pearson Chi-squared test to assess for significance. Results A total of 2409 patients were referred to the orthopedic department with injuries. A 35.6% decrease in total referrals was made during the COVID-19 pandemic. Analysis of cycling-specific injuries demonstrated a statistically significant increase in referrals to the orthopedic department during the COVID-19 pandemic. A statistically significant difference in upper limb trauma was also observed during the COVID-19 pandemic. Patterns of management, namely operative vs. non-operative management, did not demonstrate a difference in the two time periods. Discussion This study highlights that during the COVID-19 pandemic, cycling behavior changed with more patients suffering orthopedic injuries as a result. Orthopedic departments may need to plan for this change in behaviors with more capacity being created to manage the demand. Conclusion Cycling-related injuries referred to the orthopedic department increased during the pandemic.

Specific considerations in female patients with patellar instability: current concepts.

Prior literature suggests that patellofemoral instability (PFI) is significantly more prevalent in women than in men. This higher prevalence is commonly attributed to anatomical differences between sexes, particularly with patellofemoral alignment. These differences encompass a higher rate of trochlear dysplasia (TD), patella alta, an increased Q angle, and soft tissue imbalances. In recent years, worse outcomes have been reported in female patients after patellofemoral stabilization surgery using medial patellofemoral ligament reconstruction (MPFLr) alone or in combination with a tibial tubercle osteotomy (TTO), for this reason an "à la carte" plan (addressing the individuals anatomical risk factors) could be more appropriate for female patients.

Waste not, want not: Value chain stakeholder attitudes to surplus dairy calf management in Australia.

The management of surplus dairy calves in Australia has traditionally been influenced by the economic viability of different practices. When beef prices are favourable, more surplus calves are raised for beef, and when beef prices are low, more calves are killed in the first few days of life. Early life killing of surplus calves may however threaten the dairy industry's social licence to operate. The aim of this study was to describe the views of value chain stakeholders regarding the management of surplus calves. Representatives from seven post-farm gate organisations participated in semi-structured interviews and were asked about their views on current practices, alternatives to early life killing and how best to implement change. Responses were analysed using inductive thematic analysis and were organised into three themes: (1) ethics of surplus calf management; (2) economics of surplus calf management; and (3) moving towards solutions including approaches to affecting change. We conclude that stakeholders widely recognised early life killing of surplus calves as a threat to the industry's social licence. Whilst technical solutions such as beef on dairy breeding programmes were cited as important, participants emphasised that implementing sustainable solutions will require collaboration, leadership, and commitment by all stakeholders along the value chain.

Developing a prototype digital risk mitigation pathway for children and young people admitted to acute paediatric NHS care in mental health crisis: Protocol of the Safety Assessment in Paediatric healthcare Environments (SAPhE) pathway study.

Background: Globally, there are increasing numbers of Children and young people (CYPs) experiencing a mental health crisis requiring admission to acute paediatric inpatient care. These CYPs can often experience fluctuating emotional states accompanied by urges to self-harm or attempt to end their life, leading to reduced safety and poorer experiences. Currently, in the UK National Health Service (NHS) there are no standardised, evidence-based interventions in acute paediatric care to mitigate or minimise immediate risk of self-harm and suicide in CYP admitted with mental health crisis. Objective: To outline the protocol for the SAPhE Pathway study which aims to: 1) identify and prioritise risk mitigation strategies to include in the digital prototype, 2) understand the feasibility of implementing a novel digital risk mitigation pathway in differing NHS contexts, and 3) co-create a prototype digital risk mitigation pathway. Methods: This is a multi-centre study uses a mixed-methods design. A systematic review and exploratory methods (interviews, surveys, and focus groups) will be used to identify the content and feasibility of implementing a digital risk mitigation pathway. Participants will include healthcare professionals, digital experts and CYP with experience of mental health conditions. Data will be collected between January 2022 and March 2023 and analysed using content and thematic analysis, case study, cross-case analysis for qualitative data and descriptive statistics for quantitative data. Findings will inform the experience-based co-design workshops. Ethics and Dissemination: The study received full ethical approval from NHS REC [Ref: 22/SC/0237 and 22/WM/0167]. Findings will be made available to all stakeholders using multiple approaches.

2-λ5-Phosphaquinolin-2-ones as Non-cytotoxic, Targetable, and pH-Stable Fluorophores.

Several phosphaquinolinone derivatives have been synthesized and characterized to explore their usefulness in the realm of cell imaging. Solution-state photophysical properties in both aqueous and organic solutions were collected for these derivatives. Additionally, CCK-8 cell viability assays and fluorescent imaging in HeLa cells incubated with the new heterocyclic derivatives show evidence of favorable cell permeability, cell viability, and moderate intracellular localization when appended with the well-known morpholine targeting motif.

Maternal Provisioning of Alkaloid Defenses are Present in Obligate but not Facultative Egg Feeding Dendrobatids.

Poison frogs sequester alkaloid defenses from a diet of largely mites and ants. As a result, frogs are defended against certain predators and microbial infections. Frogs in the genus Oophaga exhibit complex maternal care, wherein mothers transport recently hatched tadpoles to nursery pools and return regularly to supply developing tadpoles with unfertilized (nutritive) eggs. Developing tadpoles are obligate egg feeders. Further, female O. pumilio and O. sylvatica maternally provision their nutritive eggs with alkaloid defenses, providing protection to their developing tadpoles at a vulnerable life-stage. In another genus of poison frog, Ranitomeya, tadpoles only receive and consume eggs facultatively, and it is currently unknown if mothers also provision these eggs (and thus their tadpoles) with alkaloid defenses. Here, we provide evidence that mother frogs of another species in the genus Oophaga (Oophaga granulifera) also provision alkaloid defenses to their tadpoles. We also provide evidence that Ranitomeya imitator and R. variabilis eggs and tadpoles do not contain alkaloids, suggesting that mother frogs in this genus do not provision alkaloid defenses to their offspring. Our findings suggest that among dendrobatid poison frogs, maternal provisioning of alkaloids may be restricted to the obligate egg-feeding members of Oophaga.

Public perceptions of potential adaptations for mitigating heat stress on Australian dairy farms.

Temperature variability resulting from climate change poses challenges around the world for livestock production and the welfare of the animals in these systems. As animal industries attempt to combat these challenges, it is vital to understand how potential changes implemented by farmers resonate with societal values. The aims of this study were to determine how different proposed changes to mitigate heat stress in dairy cattle influence public perceptions toward Australian dairy farm systems, including perceptions of (1) cow welfare, (2) confidence in the industry, and (3) trust in farmers. Participants were presented with 1 of 4 treatments representing a potential solution to mitigate heat stress in dairy cattle: (1) indoor system (a fully indoor barn), (2) choice system (cows have agency to choose to be indoors or outdoors), (3) gene edition + pasture (cows are genetically modified to become more resilient to heat stress), and (4) pasture (outdoor system that is currently used in Australia, but the farmer plants more trees). Participants were then asked to respond to questions on a 7-point Likert scale. Questions were about cow welfare (3 questions), confidence in dairy industry (4 questions), and trust in farmers (9 questions), with each section followed by an open-ended question for participants to explain their answers. Participants perceived cow welfare to be the lowest in the indoor system (2.80 ± 0.10), followed by gene edition + pasture (4.48 ± 0.11), with choice and pasture systems being the highest but not different from each other (5.41 ± 0.11 and 5.32 ± 0.11, respectively). Confidence in the dairy industry was lower among participants in the indoor (4.78 ± 0.08) compared with participants assigned to the choice (5.28 ± 0.08) or pasture (5.25 ± 0.08) systems. Confidence was also lower among participants in the gene edition (4.95 ± 0.08) compared with the choice system. Trust in farmers was similar across all treatments. Our results provide the first evidence that the Australian public may be reluctant to accept heat stress mitigation strategies that either do not allow cows to have access to pasture or those that include gene-editing technologies.

Efficient inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by sulfuration with solubilized elemental sulfur.

Hydrogen sulfide (H2S), carbon monoxide (CO), and nitric oxide (NO) have garnered increasing scientific interest in recent decades due to their classifications as members of the gasotransmitter family of signaling molecules. Due to the versatility of sulfur redox chemistry in biological systems, H2S specifically is being studied for its ability to modulate cellular redox environments, particularly through the downstream production of oxidized sulfur species. A major mechanism of this regulation is through a posttranslational modification known as persulfidation, where oxidized sulfur atoms are appended to free cysteine in proteins. Currently, it is difficult to discern the activity of H2S itself versus these oxidized sulfur species, particularly sulfane sulfur (S0). We have previously developed a method of solvating S8, a source of pure S0, to more accurately study persulfidation and sulfuration in general. Here, we apply this pure S0 to glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which has previously been shown to be inhibited by S0-containing polysulfides via persulfidation. Using solvated S0, we demonstrate that native, reduced GAPDH can be completely inhibited by sulfuration with S0. Further, oxidized GAPDH activity cannot be rescued using S0, demonstrating that it is the oxidation of reduced GAPDH by S0 that curtails its activity. We also compare inhibition of GAPDH by pure S0 to different polysulfides and demonstrate the modulating effects that pendant alkyl groups have on GAPDH inhibition. These results highlight the promise of this novel, simplified system for the study of S0.

Dose-dependent alkaloid sequestration and N-methylation of decahydroquinoline in poison frogs.

Sequestration of chemical defenses from dietary sources is dependent on the availability of compounds in the environment and the mechanism of sequestration. Previous experiments have shown that sequestration efficiency varies among alkaloids in poison frogs, but little is known about the underlying mechanism. The aim of this study was to quantify the extent to which alkaloid sequestration and modification are dependent on alkaloid availability and/or sequestration mechanism. To do this, we administered different doses of histrionicotoxin (HTX) 235A and decahydroquinoline (DHQ) to captive-bred Adelphobates galactonotus and measured alkaloid quantity in muscle, kidney, liver, and feces. HTX 235A and DHQ were detected in all organs, whereas only DHQ was present in trace amounts in feces. For both liver and skin, the quantity of alkaloid accumulated increased at higher doses for both alkaloids. Accumulation efficiency in the skin increased at higher doses for HTX 235A but remained constant for DHQ. In contrast, the efficiency of HTX 235A accumulation in the liver was inversely related to dose and a similar, albeit statistically nonsignificant, pattern was observed for DHQ. We identified and quantified the N-methylation of DHQ in A. galactonotus, which represents a previously unknown example of alkaloid modification in poison frogs. Our study suggests that variation in alkaloid composition among individuals and species can result from differences in sequestration efficiency related to the type and amount of alkaloids available in the environment.

Dose-dependent alkaloid sequestration and N-methylation of decahydroquinoline in poison frogs

Sequestration of chemical defenses from dietary sources is dependent on the availability of compounds in the environment and the mechanism of sequestration. Previous experiments have shown that sequestration efficiency varies among alkaloids in poison frogs, but little is known about the underlying mechanism. The aim of this study was to quantify the extent to which alkaloid sequestration and modification are dependent on alkaloid availability and/or sequestration mechanism. To do this, we administered different doses of histrionicotoxin (HTX) 235A and decahydroquinoline (DHQ) to captive-bred Adelphobates galactonotus and measured alkaloid quantity in muscle, kidney, liver, and feces. HTX 235A and DHQ were detected in all organs, whereas only DHQ was present in trace amounts in feces. For both liver and skin, the quantity of alkaloid accumulated increased at higher doses for both alkaloids. Accumulation efficiency in the skin increased at higher doses for HTX 235A but remained constant for DHQ. In contrast, the efficiency of HTX 235A accumulation in the liver was inversely related to dose and a similar, albeit statistically nonsignificant, pattern was observed for DHQ. We identified and quantified the N-methylation of DHQ in A. galactonotus, which represents a previously unknown example of alkaloid modification in poison frogs. Our study suggests that variation in alkaloid composition among individuals and species can result from differences in sequestration efficiency related to the type and amount of alkaloids available in the environment.

Hydrolysis-Based Small-Molecule Hydrogen Selenide (H2Se) Donors for Intracellular H2Se Delivery.

Hydrogen selenide (H2Se) is a central metabolite in the biological processing of selenium for incorporation into selenoproteins, which play crucial antioxidant roles in biological systems. Despite being integral to proper physiological function, this reactive selenium species (RSeS) has received limited attention. We recently reported an early example of a H2Se donor (TDN1042) that exhibited slow, sustained release through hydrolysis. Here we expand that technology based on the P═Se motif to develop cyclic-PSe compounds with increased rates of hydrolysis and function through well-defined mechanisms as monitored by 31P and 77Se NMR spectroscopy. In addition, we report a colorimetric method based on the reaction of H2Se with NBD-Cl to generate NBD-SeH (λmax = 551 nm), which can be used to detect free H2Se. Furthermore, we use TOF-SIMS (time of flight secondary ion mass spectroscopy) to demonstrate that these H2Se donors are cell permeable and use this technique for spatial mapping of the intracellular Se content after H2Se delivery. Moreover, these H2Se donors reduce endogenous intracellular reactive oxygen species (ROS) levels. Taken together, this work expands the toolbox of H2Se donor technology and sets the stage for future work focused on the biological activity and beneficial applications of H2Se and related bioinorganic RSeS.

Subcellular Targeted Nanohoop for One- and Two-Photon Live Cell Imaging.

Fluorophores are powerful tools for interrogating biological systems. Carbon nanotubes (CNTs) have long been attractive materials for biological imaging due to their near-infrared excitation and bright, tunable optical properties. The difficulty in synthesizing and functionalizing these materials with precision, however, has hampered progress in this area. Carbon nanohoops, which are macrocyclic CNT substructures, are carbon nanostructures that possess ideal photophysical characteristics of nanomaterials, while maintaining the precise synthesis of small molecules. However, much work remains to advance the nanohoop class of fluorophores as biological imaging agents. Herein, we report an intracellular targeted nanohoop. This fluorescent nanostructure is noncytotoxic at concentrations up to 50 µM, and cellular uptake investigations indicate internalization through endocytic pathways. Additionally, we employ this nanohoop for two-photon fluorescence imaging, demonstrating a high two-photon absorption cross-section (65 GM) and photostability comparable to a commercial probe. This work further motivates continued investigations into carbon nanohoop photophysics and their biological imaging applications.

The Dispensable Surplus Dairy Calf: Is This Issue a "Wicked Problem" and Where Do We Go From Here?

Surplus dairy calves consist of all dairy bull calves and any heifer calves not needed as replacements for the milking herd. The fate of these surplus calves varies by region; for example, in Australia and New Zealand they are often sold as "bobby" calves and slaughtered within the first weeks of life; whereas, in North America they are normally sold within the first weeks of life but reared for 16-18 weeks as veal or longer as dairy beef. Regardless of region, demand for these calves is often very low, driving down prices and in some cases leaving farmers with no alternative options other than on-farm euthanasia. The notion that dairy cows must give birth to produce milk and that the calves are immediately separated from the dam, many of which will end up immediately being sold as surplus calves, has become a topic of public concern. These concerns have increased given the growing number of pictures and stories in the media of on-farm euthanasia, dairy calves being transported at very young ages and frequently receiving sub-standard levels of care. In this paper we describe the status quo of this complex, value-laden issue that without transformative change is at great risk for continued criticism from the public. Moreover, despite many attempts at refinement of the existing approach (i.e., the pursuit of technical improvements), little has changed in terms of how these surplus dairy calves are managed and so we predict that on its own, this approach will likely fail in the long run. We then set out how the current surplus calf management practices could be viewed to fit the definition of a "wicked problem." We conclude by calling for new research using participatory methodologies that include the voice of all stakeholders including the public, as a first step in identifying sustainable solutions that resonate with both society and the livestock industry. We briefly discuss three participatory methodologies that have successfully been used to develop sustainable solutions for other complex problems. Adoption of these types of methodologies has the potential to help position the dairy industry as a leader in sustainable food production.

Highly efficient H2S scavengers via thiolysis of positively-charged NBD amines.

H2S is a well-known toxic gas and also a gaseous signaling molecule involved in many biological processes. Advanced chemical tools that can regulate H2S levels in vivo are useful for understanding H2S biology as well as its potential therapeutic effects. To this end, we have developed a series of 7-nitro-1,2,3-benzoxadiazole (NBD) amines as potential H2S scavengers. The kinetic studies of thiolysis reactions revealed that incorporation of positively-charged groups onto the NBD amines greatly increased the rate of the H2S-specific thiolysis reaction. We demonstrate that these reactions proceed effectively, with second order rate constants (k 2) of >116 M-1 s-1 at 37 °C for NBD-S8. Additionally, we demonstrate that NBD-S8 can effectively scavenge enzymatically-produced and endogenous H2S in live cells. Furthering the biological significance, we demonstrate NBD-S8 mediates scavenging of H2S in mice.

Modified cyclodextrins solubilize elemental sulfur in water and enable biological sulfane sulfur delivery.

An important form of biological sulfur is sulfane sulfur, or S0, which is found in polysulfide and persulfide compounds as well as in elemental sulfur. Sulfane sulfur, often in the form of S8, functions as a key energy source in the metabolic processes of thermophilic Archaean organisms found in sulfur-rich environments and can be metabolized both aerobically and anaerobically by different archaeons. Despite this importance, S8 has a low solubility in water (∼19 nM), raising questions of how it can be made chemically accessible in complex environments. Motivated by prior crystallographic data showing S8 binding to hydrophobic motifs in filamentous glycoproteins from the sulfur reducing Staphylothermus marinus anaerobe, we demonstrate that simple macrocyclic hydrophobic motifs, such as 2-hydroxypropyl ß-cyclodextrin (2HPß), are sufficient to solubilize S8 at concentrations up to 2.0 ± 0.2 mM in aqueous solution. We demonstrate that the solubilized S8 can be reduced with the common reductant tris(2-carboxyethyl)phosphine (TCEP) and reacts with thiols to generate H2S. The thiol-mediated conversion of 2HPß/S8 to H2S ranges from 80% to quantitative efficiency for Cys and glutathione (GSH). Moreover, we demonstrate that 2HPß can catalyze the Cys-mediated reduction of S8 to H2S in water. Adding to the biological relevance of the developed systems, we demonstrate that treatment of Raw 264.7 macrophage cells with the 2HPß/S8 complex prior to LPS stimulation decreases NO2 - levels, which is consistent with known activities of bioavailable H2S and sulfane sulfur. Taken together, these investigations provide a new strategy for delivering H2S and sulfane sulfur in complex systems and more importantly provide new insights into the chemical accessibility and storage of S0 and S8 in biological environments.

Rapid Aspirin Desensitization is Safe and Feasible in Patients With Stable and Unstable Coronary Artery Disease: A Single-Center Experience.

AIMS: There are limited data on aspirin (ASA) desensitization for patients with coronary disease. We present our experience with a rapid nurse-led oral desensitization regimen in patients with aspirin sensitivity undergoing coronary angiography. METHODS: This single-center retrospective observational study includes patients with a history of ASA sensitivity undergoing coronary angiography with intent to perform percutaneous coronary intervention (PCI). RESULTS: Between January 2012 and January 2017, 24 patients undergoing coronary angiography for stable coronary disease (7 cases) or acute coronary syndromes (non-ST-segment myocardial infarction [NSTEMI; 8 cases], STEMI [9 cases]) underwent aspirin desensitization having reported previous reactions to aspirin. At initial presentation, previous sensitivity reactions were reported as: mucocutaneous reactions in 17 patients (urticaria in 3 [13%], nonurticarial rash in 6 [25%], angio-oedema in 8 [33%]), respiratory sensitivity in 4 (17%), and systemic anaphylactoid reactions in 3 (13%). Seventeen (71%) patients underwent PCI. Desensitization was acutely successful in 22 (92%) patients and unsuccessful in 2 (8%) patients who both had a single short-lived episode of acute bronchospasm treated successfully with nebulized salbutamol. Fifteen successfully desensitized patients completed 12 months of aspirin; no patient had recurrent hypersensitivity reaction. Aspirin was stopped prior to 12 months in 7 patients (replaced by warfarin [1 case], no antiplatelet or single antiplatelet clinically indicated and clopidogrel chosen [4 cases], patient choice without evidence of recurrent hypersensitivity [1 case], and death due to cardiogenic shock following STEMI [1 case]). CONCLUSION: A rapid aspirin desensitization protocol is safe and effective across a broad spectrum of hypersensitivity reactions and clinical presentations.

Effects of sulfane sulfur content in benzyl polysulfides on thiol-triggered H2S release and cell proliferation.

Investigations into hydrogen sulfide (H2S) signaling pathways have demonstrated both the generation and importance of persulfides, which are reactive sulfur species that contain both reduced and oxidized sulfur. These observations have led researchers to suggest that oxidized sulfur species, including sulfane sulfur (S0), are responsible for many of the physiological phenomena initially attributed to H2S. A common method of introducing S0 to biological systems is the administration of organic polysulfides, such as diallyl trisulfide (DATS). However, prior reports have demonstrated that commercially-available DATS often contains a mixture of polysulfides, and furthermore a lack of structure-activity relationships for organic polysulfides has limited our overall understanding of different polysulfides and their function in biological systems. Advancing our interests in the chemical biology of reactive sulfur species including H2S and S0, we report here our investigations into the rates and quantities of H2S release from a series of synthetic, pure benzyl polysulfides, ranging from monosulfide to tetrasulfide. We demonstrate that H2S is only released from the trisulfide and tetrasulfide, and that this release requires thiol-mediated reduction in the presence of cysteine or reduced glutathione. Additionally, we demonstrate the different effects of trisulfides and tetrasulfides on cell proliferation in murine epithelial bEnd.3 cells.

The Role of the Specialist Nurse in Gynaecological Cancer.

PURPOSE OF REVIEW: To explore the role of the specialist nurse within gynaecological cancer. RECENT FINDINGS: There are many different job titles associated with the role of the specialist nurse. Nursing roles are evolving not only to meet the increasing demands on services but also within the ever changing landscape of cancer treatments and improvement in survival. Women and their families need specialist nurses to guide and support them on their cancer journey, along the treatment trajectory and into survivorship. This paper explores specialist nurse roles generally, and within our service which have been adapted to meet service and patient needs within a gynaecological cancer centre. Irrelevant of title, specialist nurses are best suited to meet the patients' needs. The fundamental ethos of the care should always remain having the patients' best interest at heart, acting as their advocate - in essence giving them a voice when they need it.

Light-Activated COS/H2S Donation from Photocaged Thiocarbamates.

Hydrogen sulfide (H2S) is an important biomolecule, and responsive chemical tools for its delivery are needed. Here, we utilize the photocleavable o-nitrobenzyl group to unmask caged thiocarbamates and to access photoactivated H2S releasing molecules. These donors function by the initial release of carbonyl sulfide (COS), which is quickly hydrolyzed to H2S by carbonic anhydrase (CA). Our investigations demonstrate that o-nitrobenzyl-caged thiocarbamates can serve as a donor platform for the bio-orthogonal stimulated release of COS/H2S.

Variable Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio are Perceived as Differences in Palatability to Arthropods.

Conspicuously colored dendrobatid frogs sequester alkaloid defenses from dietary arthropods, resulting in considerable alkaloid variation among populations; however, little is known about how variation is perceived as a defense against predators. Previous studies have found variable alkaloids in the dendrobatid Oophaga pumilio to be associated with differences in toxicity to laboratory mice, suggesting variable defenses are important. Arthropods are natural predators that use chemoreception to detect prey, including frogs, and may therefore perceive variation in alkaloid profiles as differences in palatability. The goal of the present study is to determine how arthropods respond to variable alkaloid defenses in O. pumilio. Frog alkaloids were sampled from individual O. pumilio from ten geographic locations throughout the Bocas del Toro region of Panama and the Caribbean coast of Costa Rica. Alkaloid extracts were used in feeding bioassays with the vinegar fly Drosophila melanogaster and the ant Ectatomma ruidum. Both species of arthropods fed significantly less on frog alkaloid extracts when compared to controls, and differences in alkaloid palatability were observed among frog populations, as well as between sexes and life stages within a population. Differences in alkaloid quantity, richness, and type were the main predictors of arthropod palatability. Our findings also represent the first direct evidence of a palatability spectrum in a vertebrate that sequesters chemical defenses from dietary sources. Further, the presence of a palatability spectrum suggests that variable alkaloid defenses in O. pumilio are ecologically relevant and play an important role in natural predator-prey interactions, particularly with respect to arthropod predators.