Mount Allison University

The formation and evolution of arc‐backarc systems govern crustal production in some of the most volcanically and hydrothermally active environments on Earth. This study presents the first complete three‐dimensional density model of the active arc‐backarc system in the southwest Pacific comprising the Lau Basin and Tofua arc. Seafloor density and crustal thickness maps reveal changes in crustal composition and growth rates throughout the basin and along the volcanic arc. Crustal thickness varies significantly between the different centers of accretion (i.e., assemblages), resulting from seafloor spreading and subsurface melt accumulation below volcanic fields. Volumetric growth rates were calculated for each assemblage, corresponding to their respective contribution to basin expansion. The highest crustal density and growth rates are thought to be related to a mantle‐derived melt source entering the basin from the north around the edge of the subducting Pacific Plate. This study shows that the inverse modeling approach can be applied to global gravity data sets to characterize and quantify the density and thickness of the crust anywhere in the oceans.

Strains from the picocyanobacteria genus Synechococcus are currently found across a wide range of photoperiods and photosynthetically active radiation. Future scenarios now forecast range expansions of marine Synechococcus into new photic regimes. We found that strains of temperate, coastal phycocyanin‐rich and phycoerythrin‐rich Synechococcus grew fastest under moderate photosynthetically active radiation, and a 24‐h photoperiod, despite a cumulative diel photon dose equivalent to conditions where growth was slower, under higher light and shorter photoperiods. Under optimal conditions, a phycoerythrin‐rich Synechococcus strain achieved a highest recorded cyanobacterial chlorophyll‐specific exponential growth rate (μ) of 4.5 d⁻¹. Two phycoerythrin‐rich strains demonstrated wider ability to modulate light capture capacity, whereas two phycocyanin‐rich strains showed less change in light capture across increasing cumulative diel photon dose. All four coastal strains showed a decrease of effective absorption cross‐section for photosystem II photochemistry, vs. increasing cumulative diel photosynthetically active radiation doses. Within each strain, μ showed consistent, saturating responses to increasing cumulative diel photosystem II electron flux, with more variations in responses of μ to cumulative photosynthetically usable radiation. As photoperiod opportunists, coastal picocyanobacteria show potential to expand into longer photic regimes as higher latitudes warm.

Plants make up more than one quarter of all species listed under Canada’s Species at Risk Act, but very few have improved in status over time. Ineffective legal protections, lack of public awareness, difficulties in prioritizing species, and a scarcity of research relevant to the recovery of plant species at risk are some of the many challenges facing effective plant conservation in Canada. We used an online survey to ask 243 people who work in plant conservation or who do research in plant ecology or evolution to assess the state of plant conservation in Canada and to identify the actions needed to improve it. Most respondents agreed that Canada is underperforming or merely average when it comes to conserving plants. Based on their responses, we outline a set of recommendations that could form the basis of a national strategy for plant conservation in Canada. These include greater advocacy for habitat protection, connecting researchers with funding opportunities, supporting graduate students working on research related to plant conservation, increasing public awareness of plants, collaborating with and respecting Indigenous knowledge holders, promoting collaboration between researchers and local conservation groups, and increasing capacity to assess the status of species that are potentially at risk.

Warmer and more variable temperatures have been implicated in the recent decline of Atlantic salmon (Salmo salar) in Eastern Canada. To date, we know little on how ecologically relevant thermal fluctuations affect swimming performance in fishes. The goal of this study is to determine the effects of warm versus cool diel thermal variability on swimming efficiency and the speed limit for sustainable aerobically fueled swimming. We acclimated wild S. salar juveniles to a cool and a warm ecologically realistic diel thermal profile (16–21 and 19–24°C), and then tested individuals over a common acute change in temperature (16–24°C). We measured metabolic rate and swimming kinematics at a range of swimming speeds, at five temperatures (16, 18, 20, 22, and 24°C) and calculated swimming efficiency. Our temperature acclimation did not appear to significantly affect energetic and kinematic swimming efficiency, but acute exposure to high temperature did increase overall metabolic rate. It appears that wild S. salar can swim efficiently and sustainably during both acute cool and warm exposures, and after acclimation to diel thermal variation of 16–21 or 19–24°C.

This article is an appreciative exegesis of Steven Burns's article “If a Lion Could Talk.” In his essay, Burns clarifies Ludwig Wittgenstein's enigmatic remark “If a lion could talk, we wouldn't be able to understand him” by locating it within the broader context of Wittgenstein's work in the philosophy of psychology. We read Burns's interpretation of the remark as opening core Wittgensteinian issues of meaning and (mis)understanding, and we situate it within the context of the work of Burns's teacher, Peter Winch. Our discussion is a close exegesis of the immediate content of the lion remark and it highlights connections to Wittgenstein's remarks on James George Frazer's The Golden Bough. We show how Burns and Winch employ Wittgenstein's methods of dissolving philosophical puzzles by drawing attention to intermediate familiar cases. We conclude with some impressionistic remarks about Socrates in a short discussion of the difficulty of the philosophical technique and activity Burns demonstrates and recommends.

The proportions of carbon (C), nitrogen (N), and phosphorus (P) in surface ocean particulate matter deviate greatly from the canonical Redfield Ratio (C:N:P = 106:16:1) in space and time with significant implications for global carbon storage as this matter reaches the deep ocean. Recent work has revealed clear latitudinal patterns in C:N:P, yet the relative importance of ecological, physiological, or biochemical processes in creating these patterns is unclear. We present high-resolution, concurrent measurements of particulate C:N:P, macromolecular composition, environmental conditions, and plankton community composition from a transect spanning a subtropical-subpolar boundary, the North Pacific Transition Zone. We find that the summed contribution of macromolecules to particulate C, N, and P is consistent with, and provides interpretation for, particulate C:N:P patterns. A decline in particulate C:N from the subtropical to subpolar North Pacific largely reflects an increase in the relative contribution of protein compared to carbohydrate and lipid, whereas variation in C:P and N:P correspond to shifts in protein relative to polyphosphate, DNA, and RNA. Possible causes for the corresponding trends in C:N and macromolecular composition include physiological responses and changes in community structure of phytoplankton, which represented approximately 1/3 rd of particulate C across the transect. Comparison with culture experiments and an allocation-based model of phytoplankton macromolecular composition suggest that physiological acclimation to changing nutrient supply is the most likely explanation for the latitudinal trend in C:N, offering both a mechanistic interpretation and biochemical basis for large-scale patterns in C:N:P.

Zinc and selenium are essential minerals for human nutrition. Reliable biomarkers of zinc status and selenium status in humans are therefore important. This work investigates a novel portable X-ray fluorescence (XRF) method with the ability to rapidly assess zinc and selenium in nail clippings. This approach used a mono-energetic X-ray beam to excite characteristic X-rays from the clippings. Nail clippings were obtained from the Mother and Infant Nutrition Investigation (MINI), a study designed to assess nutrition in a population of women and their breastfed children in New Zealand. Twenty mother-infant pairings were selected to provide nail clippings at two time points (visit 1 at 3 months postpartum; visit 2 at 6 months postpartum). Nail clippings from each mother-infant pairing were divided into three groupings of clippings prior to analysis: those obtained from a big toe of the mother, those from the other toes of the mother, and those from the toes and fingers of the infant. Clippings were prepared and mounted prior to XRF measurement, providing four distinct fragments from each clipping grouping. These fragments were assessed by XRF using a measurement time of either 300 s (visit 1) or 180 s (visit 2). XRF results were determined through both an automated system output and an analysis of the X-ray energy spectrum. Following this assessment of zinc and selenium with the non-destructive XRF method, clippings were measured for zinc and selenium concentration using a “gold standard” technique of inductively coupled plasma mass spectrometry (ICP-MS). Mean ICP-MS concentrations ranged from 122 μg/g to 127 μg/g for zinc, and from 0.646 μg/g to 0.659 μg/g for selenium. Precision, assessed by a relative standard deviation of measurement, was superior for ICP-MS relative to XRF. For both zinc and selenium, XRF results were compared with ICP-MS concentrations. Linear equations of best fit were determined for each comparison between XRF and ICP-MS results. Coefficients of determination (r²) were stronger for zinc (from 0.74 to 0.95) than selenium (from 0.53 to 0.70). A decrease in XRF measurement time from 300 s to 180 s did not appear to adversely affect the correlation between XRF and ICP-MS results. Using the mono-energetic portable XRF method, the correlation of XRF zinc results with ICP-MS zinc concentrations was improved over previous findings, and selenium measurement was reported for the first time. The method may prove useful for future applications to trace element analysis using nail clippings as a biomarker.

While it is philosophically contested whether nonlinguistic animals can have conceptual capabilities, it is also philosophically contested whether one can even empirically test for such capabilities. I draw from Sellars’ work on psychological nominalism to develop an empirically tractable means of distinguishing between tasks that require conceptual capabilities and those that do not. Tasks that require conceptual capabilities are those that require awareness of abstract relations, whereas tasks that can be solved merely through Sellarsian picturing do not. I argue that relational matching-to-sample tasks cannot be solved through picturing and therefore require awareness of the abstract relations of same and different. Crows and amazons have both been able to succeed at relational matching-to-sample tasks; therefore, there are at least some nonlinguistic animals that have conceptual capabilities. Finally, I consider the objection that one cannot attribute conceptual capabilities without also attributing knowledge, and Sellarsian conditions for knowledge are beyond the capabilities of any nonlinguistic animal. In response, I argue that Sellarsian conditions for knowledge only require an implicit grasp of the is/looks distinction and empirical work with chimpanzees on their understanding of the appearance/reality distinction demonstrates that they can meet this standard. Therefore, language is not necessary for meeting Sellarsian conditions for knowledge.

We found that PhycoErythrin-rich Synechococcus achieved faster growth rates (µ), across the spectral bandwidths from 405 – 730 nm, under 2.5 µM [O₂], characteristic of Oxygen Minimum Zones (OMZs), than under 250 µM [O₂], whereas PhycoCyanin-rich strain showed generally similar µ under 2.5 and 250 µM [O₂]. For PhycoCyanin- and PhycoErythrin-rich Synechococcus , µ showed also positive linear responses to both Phycobiliproteins:Chlorophyll a , and to cumulative diel PSII electron flux, although the relations vary across strain and [O₂]. Electron transport downstream of Photosystem II was generally higher for both PhycoCyanin- and PhycoErythrin-rich strains under 250 µM [O₂], since cyanobacteria show strong capacity for electron flow away from PSII to O₂, particularly under excess excitation. Even though electron transport was faster under 250 µM [O₂], the PhycoErythrin-rich strain showed a higher growth yield of electron transport under 2.5 µM [O₂]. PhycoErythrin-rich Synechococcus are currently typically found at greater depths, and lower light, than are PhycoCyanin-rich strains, but we suggest that the PhycoErythrin-rich strains are actually limited to lower light by an interaction between light and full air-saturated [O₂]. In expanding Oxygen Minimum Zones PhycoErythrin-rich strains will likely exploit higher light niches, across a wider spectral range.

Decision-making in the real world involves multiple abilities. The main goal of the current study was to examine the abilities underlying the Preschool Gambling task (PGT), a preschool variant of the Iowa Gambling task (IGT), in the context of an integrative decision-making framework. Preschoolers (n = 144) were given the PGT along with four novel decision-making tasks assessing either decision-making under ambiguity or decision-making under risk. Results indicated that the ability to learn from feedback, to maintain a stable preference, and to integrate losses and gains contributed to the variance in decision-making on the PGT. Furthermore, children’s awareness level on the PGT contributed additional variance, suggesting both implicit and explicit processes are involved. The results partially support the integrative decision-making framework and suggest that multiple abilities contribute to individual differences in decision-making on the PGT.

The Arctic is warming three times faster than the global average, imposing challenges to cold-adapted fish, like Arctic char (Salvelinus alpinus). We evaluated stress and metabolic responses of Arctic char to different thermal acclimation scenarios to determine if responses to thermal variation differed from those to stable exposures. Fish were exposed for 7 days to one of 4 treatments: (1) control (12 °C), (2) mean (16 °C), corresponding to the mean temperature of the diel thermal cycle, (3) constant high temperature (20 °C), and (4) diel thermal cycling (12 to 20 °C every 24 h). Exposure to 20 °C causes increases plasma lactate and glucose, an imbalance in antioxidant systems, and oxidative stress in the liver. The 20 °C treatment also elevated fractional rates of protein synthesis and caused oxidative stress in the heart. Stress responses were more pronounced in diel thermal cycling than in mean (16 °C) fish, indicating that peak exposure temperatures or variation are physiologically important. Cortisol was highest in diel thermal cycling fish and oxidative stress was noted in the liver. Gill Na+/K+-ATPase activity was also significantly reduced in diel thermal cycling fish, suggesting gill remodeling in response to an osmoregulatory stress. Exposure to a constant 20 °C, was more challenging than a diel thermal cycle, demonstrating the importance of daily cooling to recovery. Arctic char inhabit a thermally variable environment and understanding how this impacts their physiology will be critical for informing conservation strategies in the context of a rapidly warming Arctic.

We present a new explicit formula for the determinant that contains superexponentially fewer terms than the usual Leibniz formula. As an immediate corollary of our formula, we show that the tensor rank of the $n \times n$ determinant tensor is no larger than the n -th Bell number, which is much smaller than the previously best-known upper bounds when $n \geq 4$ . Over fields of non-zero characteristic we obtain even tighter upper bounds, and we also slightly improve the known lower bounds. In particular, we show that the $4 \times 4$ determinant over ${\mathbb{F}}_2$ has tensor rank exactly equal to 12 . Our results also improve upon the best-known upper bound for the Waring rank of the determinant when $n \geq 17$ , and lead to a new family of axis-aligned polytopes that tile ${\mathbb{R}}^n$ .

Anaplasma is an intracellular alphaproteobacteria that infects diverse blood cell types in animal hosts including small ruminants. Epidemiological and risk factors information on zoonotic anaplasmosis with respect to anaplasmosis in sheep and goats are scarce. Therefore, the objective of the current study was to estimate the prevalence, risk factors of anaplasmosis and phylogenetic investigation of A. capra in sheep and goats from Faisalabad district, Pakistan. Briefly, 384 blood samples were randomly collected from sheep and goats of Faisalabad district, Pakistan, during January to May 2022. The samples were processed for the detection of Anaplasma targeting 16S rRNA gene using PCR. The data regarding disease determinants were collected using a predesigned questionnaire. Out of 384 samples, 131 samples were found positive for Anaplasma spp. with a prevalence rate of 34.11%. The results indicated a significantly higher prevalence of anaplasmosis in goats (41.88%) compared to sheep (22.00%). In addition, the chi square indicated that housing type, tick infestation, gender, tick control practices, age, mix farming, and hygiene were significantly associated with the occurrence of disease. The analysis of multivariate logistic regression expressed gender as the significant risk factor (p = 0.0001, OR = 1.757, CI = 1.305–2.366). The acquired sequences revealed four novel isolates of A. capra (Genbank accession numbers ON834323, ON838209, ON838210, and ON838211). The phylogenetic analysis of the 16S rRNA gene of A. capra revealed three distinct clusters with 99–100% homology with other isolates from different countries. Our isolates showed higher similarity with isolates from China (KM206273, KP314237, MT799937), Pakistan (ON238129, ON238130, ON238131), Angola (MT898988), India (MZ558066), Iran (MW692362), and Turkey (MT632469) isolated from human, sheep, ticks, goats, cattle, Gaddi goat, Persian Onager (Equus hemionus onager), and Turkish goats, respectively. In conclusion, A. capra is endemic in Punjab, Pakistan, there is a need to conduct large scale surveillance studies to assess the status of this pathogen at human-animal interface as well as to develop effective preventive and control strategies to reduce the economic losses associated with anaplasmosis in small ruminants.

The objective of the current study was to examine the prevalence of eating disorder behaviours among student-athletes at a small, non-NCAA (Canadian) university, while evaluating the influence of gender, type of sport, and perceived social support. Two hundred participants (130 female, 70 male) completed an online survey that assessed participants eating disorder behaviours (EAT-26), behaviours consistent with the Adonis Complex (ACQ) and perceived social support (modified MPSS). The results revealed significant differences in eating disorder behaviour between female and male athletes, with females scoring significantly higher; yet no differences were found between how female and male athletes scored on the Adonis Complex Questionnaire. Significant differences were found between lean-sport and non-lean sport athletes, with lean sport athletes exhibiting more eating disorder behaviours. Furthermore, non-lean sport male athletes were found to score significantly higher than lean-sport male athletes for the Adonis Complex. Perceived social support was found to be negatively correlated to eating disorder behaviours and when considering gender and type of sport, accounted for unique variance in eating disorder behaviour. These results suggest that student-athletes are susceptible to negative mental health outcomes, even within the context of a smaller (and non-NCAA) university context, and eating behaviours vary among athlete and sport type. The results highlight the importance of continued research in this area and of having support systems in place for student-athletes and increasing awareness of athletic staff and coaches as to the seriousness and prevalence of eating disorder behaviours.

Adults have been found to tell lies about their physical and mental health concerns, but no research has assessed how health lies are perceived by others. The present study explored the moral acceptability of older adults’ health lies. A sample of 73 younger and 61 older adults assessed how good or bad it is for older adults to tell health lies (about physical health, mental health, medication use) to their doctor, spouse, and adult child. All health lies were rated quite negatively but lies about medication adherence and lies to doctors were rated the most negatively. Compared with younger adults, older adults were more approving of lying to a doctor about physical health but less approving of lying to one’s adult child about mental health. Across participants, those with greater depressive symptoms viewed mental health lies less negatively. Given that health lies were rated quite negatively, telling health lies may hold negative social implications for older adults.

We examined how safety leadership behaviours (“speaking about safety” and “role modeling safety”) predicted retail workers’ symptoms of post traumatic stress disorder (PTSD) and safety behavior during a health and safety crisis and the mediating role of workers’ health and safety-related fears. During the first months of the COVID-19 pandemic (i.e., March and April 2020), we surveyed retail workers in the U.S. and Canada, measuring fear of COVID-19 infection, symptoms of PTSD, self-protective safety behaviors (e.g., handwashing), and perceptions of their leaders’ safety behaviors at three time points (n1 = 505, n2 = 326, n3 = 218). In an observed variable path analysis, leader modeling of safety related directly to greater self-protection behaviors in time two only. Leader “speaking about safety” was associated with increases in employees’ fear of infection. Fear, in turn, promoted greater self-protective safety behaviors. Speaking about safety was directly and positively related to symptoms of PTSD among employees, suggesting that, during times of crisis, the benefits associated with leaders’ safety behaviors may need to be balanced with the potential for mental-health related costs. Implications for future research and practice are discussed.

Context In adults, cortisol levels show a pronounced 24-hour rhythm with a peak in the early morning. It is unknown at what age this early-morning peak in cortisol emerges during infancy, hampering the establishment of optimal dosing regimens for hydrocortisone replacement therapy in infants with an inborn form of adrenal insufficiency. Objective We aimed to characterize daily variation in salivary cortisol concentration across the first year of life. Methods We conducted a systematic review followed by an individual participant data meta-analysis of studies reporting on spontaneous (ie, not stress-induced) salivary cortisol concentrations in healthy infants aged 0-1 year. A one-stage approach using linear mixed-effects modeling was used to determine the interaction between age and time of day on cortisol concentrations. Results Through the systematic review, 54 eligible publications were identified, reporting on 29 177 cortisol observations. Individual participant data were obtained from 15 study cohorts, combining 17 079 cortisol measurements from 1904 infants. The morning/evening cortisol ratio increased significantly from 1.7 (95% CI: 1.3-2.1) at birth to 3.7 (95% CI: 3.0-4.5) at 6 to 9 months (P < .0001). Cosinor analysis using all available data revealed the gradual emergence of a 24-hour rhythm during infancy. Conclusion The early-morning peak in cortisol secretion gradually emerges from birth onwards to form a stable morning/evening ratio from age 6 to 9 months. This might have implications for hydrocortisone replacement therapy in infants with an inborn form of adrenal insufficiency.

The mantle muscle of common cuttlefish, Sepia officinalis , is responsible both for high‐magnitude and rapid movements for locomotion, as well as sustained ventilation, which require specific metabolic, electrophysiological, and structural organization. Young cuttlefish have a highly oxidative phenotype and a rapid growth rate. Here, we show high rates of oxygen consumption and protein synthesis in juveniles, and these rates decay exponentially over the first few weeks of growth. This is associated with considerable citrate synthase activity (relative to larger cuttlefish) but a lack of glucose metabolism based on zero uptake of glucose by isolated muscle sheets and minimal activity of hexokinase (similar to larger animals). In contrast to glucose metabolism in the heart, glucose metabolism in these muscle sheets was not stimulated by extracellular taurine. Previous research revealed an unusual ion channel complement in mantle myocytes, the most notable feature of which is the lack of a Na ⁺ current during depolarization. Because this adaptation is not consistent across the coleoid clade, we investigated excitation–contraction coupling. Here, mantle energetics and contractility, including the individual components of the total Ca ²⁺ flux driving contraction, were studied. Results indicate that the majority of Ca ²⁺ current underlying contractile stress development capacity in cuttlefish juveniles is not mediated by dihydropyridine‐sensitive L‐type channels, in contrast to their adult counterparts, and the sarcoplasmic reticulum contributes little to routine contractility. We had previously noted an influence of physiological levels of taurine in limiting cardiac contractility but found no analogous sensitivity in mantle muscle. Finally, transmission electron microscopy of subcellular architecture revealed the presence of sarcoplasmic tubular aggregates, suggesting that oxidative inhibition of sarcoplasmic reticulum function limits its role in this life stage.

Photosynthetic acclimation to both warming and elevated CO 2 of boreal trees remains a key uncertainty in modelling the response of photosynthesis to future climates. We investigated the impact of increased growth temperature and elevated CO 2 on photosynthetic capacity ( V cmax and J max ) in mature trees of two North American boreal conifers, tamarack and black spruce. We show that V cmax and J max at a standard temperature of 25°C did not change with warming, while V cmax and J max at their thermal optima ( T opt ) and growth temperature ( T g ) increased. Moreover, V cmax and J max at either 25°C, T opt or T g decreased with elevated CO 2 . The J max / V cmax ratio decreased with warming when assessed at both T opt and T g but did not significantly vary at 25°C. The J max / V cmax increased with elevated CO 2 at either reference temperature. We found no significant interaction between warming and elevated CO 2 on all traits. If this lack of interaction between warming and elevated CO 2 on the V cmax , J max and J max / V cmax ratio is a general trend, it would have significant implications for improving photosynthesis representation in vegetation models. However, future research is required to investigate the widespread nature of this response in a larger number of species and biomes.