Wilfrid Laurier University
  • Waterloo, Ontario, Canada
Recent publications
The contemporary rate of environmental change is faster than ever recorded. Wildlife will need to acclimate or adapt habitat selection strategies to persist in the face of rapid natural and anthropogenic change. We reviewed primary literature on cumulative effects and habitat selection frameworks that link to functional response. Our primary goal was to highlight how functional response to habitat selection can fit into current approaches that assess wildlife response to landscape disturbance including model structure, disturbance type, and spatiotemporal scales. Both functional response to habitat selection and cumulative effects assessment endeavor to capture how wildlife alter their space use across a changing landscape over time. These two methods are seldom used in combination, but together can quantify behavioral responses that may change as a function of accumulating disturbances. Most studies we reviewed included multiple measures of anthropogenic disturbance, but rarely considered how the interaction between separate disturbances may influence wildlife response. We propose integrating functional response to habitat selection and cumulative effects using resource selection functions. We identify three avenues to further expand the use of this application: (A) considering different types of cumulative effects and their interactions, (B) predicting responses over space and time, and (C) using thresholds as a path to understand biological mechanisms. Allowing disturbance responses to covary as a function of resource availability will provide meaningful comparisons of habitat selection and aid in disentangling cumulative effects interactions.
mRNA translation is a fundamental process for life. Selection of the translation initiation site (TIS) is crucial, as it establishes the correct open reading frame for mRNA decoding. Studies in vertebrate mRNAs discovered that a purine at −3 and a G at +4 (where A of the AUG initiator codon is numbered + 1), promote TIS recognition. However, the TIS context in other eukaryotes has been poorly experimentally analyzed. We analyzed in vitro the influence of the −3, −2, −1 and + 4 positions of the TIS context in rabbit, Drosophila, wheat, and yeast. We observed that −3A conferred the best translational efficiency across these species. However, we found variability at the + 4 position for optimal translation. In addition, the Kozak motif that was defined from mammalian cells was only weakly predictive for wheat and essentially non-predictive for yeast. We discovered eight conserved sequences that significantly disfavored translation. Due to the big differences in translational efficiency observed among weak TIS context sequences, we define a novel category that we termed ‘barren AUG context sequences (BACS)’, which represent sequences disfavoring translation. Analysis of mRNA-ribosomal complexes structures provided insights into the function of BACS. The gene ontology of the BACS-containing mRNAs is presented.
Background To develop and validate a prediction tool, or nomogram, for the risk of a decline in cognitive performance based on the interRAI Cognitive Performance Scale (CPS). Methods Retrospective, population-based, cohort study using Canadian Resident Assessment Instrument for Home Care (RAI-HC) data, collected between 2010 and 2018. Eligible home care clients, aged 18+, with at least two assessments were selected randomly for model derivation (75%) and validation (25%). All clients had a CPS score of zero (intact) or one (borderline intact) on intake into the home care program, out of a possible score of six. All individuals had to remain as home care recipients for the six months observation window in order to be included in the analysis. The primary outcome was any degree of worsening (i.e., increase) on the CPS score within six months. Using the derivation cohort, we developed a multivariable logistic regression model to predict the risk of a deterioration in the CPS score. Model performance was assessed on the validation cohort using discrimination and calibration plots. Results We identified 39,292 eligible home care clients, with a median age of 79.0 years, 62.3% were female, 38.8% were married and 38.6% lived alone. On average, 30.3% experienced a worsening on the CPS score within the six-month window (i.e., a change from 0 or 1 to 2, 3, 4, 5, or 6). The final model had good discrimination (c-statistic of 0.65), with excellent calibration. Conclusions The model accurately predicted the risk of deterioration on the CPS score over six months among home care clients. This type of predictive model may provide useful information to support decisions for home care clinicians who use interRAI data internationally.
Laboratory-based research dominates the fields of comparative physiology and biomechanics. The power of lab work has long been recognized by experimental biologists. For example, in 1932, Georgy Gause published an influential paper in Journal of Experimental Biology describing a series of clever lab experiments that provided the first empirical test of competitive exclusion theory, laying the foundation for a field that remains active today. At the time, Gause wrestled with the dilemma of conducting experiments in the lab or the field, ultimately deciding that progress could be best achieved by taking advantage of the high level of control offered by lab experiments. However, physiological experiments often yield different, and even contradictory, results when conducted in lab versus field settings. This is especially concerning in the Anthropocene, as standard laboratory techniques are increasingly relied upon to predict how wild animals will respond to environmental disturbances to inform decisions in conservation and management. In this Commentary, we discuss several hypothesized mechanisms that could explain disparities between experimental biology in the lab and in the field. We propose strategies for understanding why these differences occur and how we can use these results to improve our understanding of the physiology of wild animals. Nearly a century beyond Gause's work, we still know remarkably little about what makes captive animals different from wild ones. Discovering these mechanisms should be an important goal for experimental biologists in the future.
The plants of the genus Ferula (Apiaceae), with more than 180 species found worldwide, have been a source of numerous bioactive secondary metabolites. In this study, we isolate the essential oils from different parts of an Iranian endemic species Ferula xylorhachis Rech.f. -for the first time- by hydro-distillation and further characterized their chemical profile by GC/MS analysis. In addition, we evaluated their antimicrobial properties against a set of skin pathogens, namely Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. GC/MS analysis of the essential oils resulted in the identification of seventy-two compounds representing 98% and 90.2% of all volatile compounds in the aerial parts and the roots, respectively. Some of these compounds, mainly the monoterpenes and aliphatic hydrocarbons, were also detected in headspace GC/MS analysis of the dried plant parts. The oil compositions were dominated by the monoterpene hydrocarbons in the aerial parts, and aliphatic hydrocarbons in the roots. The principal chemical constituents were sabinene (17.6%), α-pinene (16.2%) and n-nonane (14%) in the essential oil from the aerial parts, and n-nonane (56.5%), 10s,11s-himachala-3(12),4-diene (6.9%) and β-himachalene (2.3%) in the essential oil from the roots. While the essential oils did not show activity against tested bacterial strains, they both exhibited antifungal activity against C. albicans at varying concentrations, which was promising in the case of roots essential oils which exhibited an MIC of 250 μg/mL. Based on our findings, the topical use of F. xylorhachis roots essential oils could be considered an alternative therapy for superficial infections caused by Candida species.
The common field lampricide, 3-trifluoromethyl-4-nitrophenol (TFM), is used to treat streams and creeks infested with highly invasive and destructive sea lamprey (Petromyzon marinus) in the tributaries of the Great Lakes. Unfortunately, amphibian deaths have been reported following stream treatments with TFM. Larval amphibians (tadpoles) are more susceptible to TFM toxicity than adult amphibians. The aim of this study was to test the toxicity of TFM in eight new tadpole cell lines from the green frog (Lithobates clamitans), wood frog (Lithobates sylvaticus), and American toad (Anaxyrus americanus). A cell viability bioassay using two fluorescent dyes, Alamar Blue and CFDA-AM, was performed following 24-h and 72-h exposures to a range of TFM concentrations. In general, TFM exposure reduced Alamar Blue fluorescence more rapidly than CFDA-AM fluorescence in tadpole cells, suggesting that Alamar Blue is perhaps a better diagnostic indicator of cell health for acute TFM cytotoxicity. At present, the in vivo 96-h LC50s of TFM are only available for L. clamitans and they correlated well with the in vitro EC50 values for the green frog tadpole cell lines in this study. The eight tadpole cell lines with different relative sensitivities to TFM cytotoxicity could prove to be useful tools in assessing next-generation lampricides in high-throughput bioassays to ensure safety in frogs before their sea lamprey-targeted application in the field.
In this paper, we investigate some polynomial conditions that arise from Euclidean geometry. First we study polynomials related to quadrilaterals with supplementary angles, this includes convex cyclic quadrilaterals, as well as certain concave quadrilaterals. Then we consider polynomials associated with quadrilaterals with some equal angles, which include convex and concave tilted kites. Some of the results are proved using Groebner bases computations.
Science is among humanity’s greatest achievements, yet scientific censorship is rarely studied empirically. We explore the social, psychological, and institutional causes and consequences of scientific censorship (defined as actions aimed at obstructing particular scientific ideas from reaching an audience for reasons other than low scientific quality). Popular narratives suggest that scientific censorship is driven by authoritarian officials with dark motives, such as dogmatism and intolerance. Our analysis suggests that scientific censorship is often driven by scientists, who are primarily motivated by self-protection, benevolence toward peer scholars, and prosocial concerns for the well-being of human social groups. This perspective helps explain both recent findings on scientific censorship and recent changes to scientific institutions, such as the use of harm-based criteria to evaluate research. We discuss unknowns surrounding the consequences of censorship and provide recommendations for improving transparency and accountability in scientific decision-making to enable the exploration of these unknowns. The benefits of censorship may sometimes outweigh costs. However, until costs and benefits are examined empirically, scholars on opposing sides of ongoing debates are left to quarrel based on competing values, assumptions, and intuitions.
The attenuation of sensory inputs via various methods has been demonstrated to impair balance control and alter locomotor behavior during human walking; however, the effects of attenuating foot sole sensation under distinct areas of the foot sole on lower extremity motor output remains poorly understood. Thus, the purpose of this study was to attenuate cutaneous feedback via regional hypothermia under five different areas of the foot sole and investigate the resultant modulation of kinematic and muscle activity during level walking. Electromyography from eight lower leg muscles, kinematics, and location of center of pressure was recorded from 48 healthy young adults completing walking trials with normal and reduced cutaneous sensation from bilateral foot soles. The results of this study highlight the modulatory response of the tibialis anterior in terminal stance (propulsion and toe-off) and medial gastrocnemius muscle throughout the entire stance phase of gait. The topographical organization of foot sole skin in response to the attenuation of cutaneous feedback from different areas of the foot sole significantly modified locomotor activity. Furthermore, the locomotor response to cutaneous attenuation under the same regions that we previously facilitated with tactile feedback do not oppose each other, suggesting different physiological changes to foot sole skin generate unique gait behaviors.
Over the past two decades, numerous developed and developing nations have witnessed a remarkable shift from manufacturing-based economies to those that center around the service sector. This development has led to a staggering growth in the consumption of energy-intensive goods, and Canada has not been immune to this trend. Despite being home to abundant energy reserves, the country’s economic expansion has manifestly relied on prodigious energy consumption. Within this context of symbiotic energy-economic growth, this study investigates the empirical relationship between energy consumption and economic growth using Canadian time-series data from 1980 to 2020. In doing so, this paper offers a vital contribution to the development of theoretical frameworks within the sphere of endogenous growth. Besides, to arrive at empirical findings, a model known as the autoregressive distributed lag (ARDL) model, renowned for its ability to discern both short- and long-term coefficients, is employed. The results reveal that economic growth has a significant positive long-run effect on energy consumption and other explanatory variables. All variables other than trade openness demonstrate a positive relationship with economic growth in the short run. From Toda-Yamamoto causality test, it is evident that there exist bidirectional causal links between economic growth and energy consumption and between economic growth and financial development. Several unidirectional causalities were also observed for other variables. Based on these findings, it is recommended that Canada boosts its investment in energy infrastructure, especially in rural and backward regions, to deliver necessary energy services. An optimal trade-off between Canada’s vast energy resources and economic growth can perhaps be achieved by minimizing the disparity in access to energy services across all parts of the country. Other policy implications are discussed.
In this paper, a deep learning based framework has been developed to predict hydrodynamic forces on a mantle-undulated propulsion robot. A multiple proper orthogonal decomposition (MPOD) algorithm has been proposed to efficiently identify fluid features near the undulating mantle of the mantle-undulated propulsion robot globally and locally. The results indicate that the L^2 error of the solution states near the undulating boundary of the proposed MPOD algorithm converges almost linearly to 0.2%. Furthermore, a hydrodynamics prediction framework has been developed based on the proposed MPOD algorithm, where a long short-term memory neural network predicts the temporal coefficients of the MPOD spatial modes. The developed framework achieves economical and reliable predictions of hydrodynamic forces acting on the undulating boundary compared to simulations and experiments. Moreover, the L^2 error of the developed framework is one to two orders of magnitude lower than that of the frameworks based on the classical POD algorithm when the degrees of freedom are consistent. Finally, the reliability of the proposed MPOD-NIROM is discussed through an offline parameter planning case of an aquatic-inspired robot. The model presented in this paper can provide support for the offline parameter planning of aquatic-inspired robots.
While living with roommates in residence presents a unique set of challenges for emerging adults who are just beginning to navigate a world of adult responsibilities and are adjusting to living with an often-unfamiliar companion, conflicts become inevitable. Common sources of conflict, such as disputes over cleaning duties or noise levels, combine with still-developing conflict resolution skills to create an escalating environment of hostility that can develop into bullying if not properly addressed. However, what remains relatively understudied is how emerging adults navigate conflict management and how conflict resolution styles mitigate such household conflicts. Employing a multi-methods approach, this study utilized quantitative (i.e., questionnaires) and qualitative (i.e., short answer questions) methods to investigate the relative influence of conflict management styles and social support on roommate victimization and bullying among 804 undergraduate students aged 18–21 years old (79% female; M = 19). Multiple hierarchal linear regressions and thematic analyses were employed to analyze the data. The findings revealed that roommate compromise predicted an increase in roommate victimization and bullying, and an inverse relationship between resolving conflict with self-interest, where increased self-interest predicted lower roommate victimization and bullying. Social support was significantly inversely related to roommate bullying and victimization, such that increased social support tended to mitigate bullying and victimization. Taken in unison, these findings convey while students may believe they are compromising, whether they are requires further investigation. This work highlights the need to teach students how to manage conflict in healthy ways while verifying the continued importance of social support.
A diamine-bis(phenolate) chromium(III) complex, CrOH[L] ([L] = dimethylaminoethylamino-N,N-bis(2-methylene-4,6-tert-butylphenolate)), 2, in the presence of tetrabutylammonium hydroxide effectively copolymerizes CO2 and cyclohexene oxide (CHO) into a polycarbonate diol. The resultant low molar mass (6.3 kg mol-1) diol is used to initiate ring-opening polymerization of rac-lactide with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) giving ABA-type block copolymers with good molar mass control through varying rac-LA-to-diol loadings and with narrow dispersities. As the degree of rac-LA incorporation increases, the glass transition temperatures (Tg) are found to decrease, whereas decomposition temperatures (Td) increase. (Diphenylphosphonimido)triphenylphosphorane (Ph2P(O)NPPh3) was used as a neutral nucleophilic cocatalyst with 2, giving phosphorus-containing polycarbonates with an Mn value of 28.5 kg mol-1, a dispersity of 1.13, a Tg value of 110 °C and a Td value of over 300 °C. A related Cr(III) complex (4) having a methoxyethyl pendent group rather than a dimethylaminoethyl group was structurally characterized as a hydroxide-bridged dimer.
Sentience is a cognitive function defined by subjective experience that is currently assumed to be a special property of animal brains. Because cognitive functions consistent with sentience including learning and decision-making are displayed by diverse intelligent systems without nervous systems including single cell amoebae, plants, and even inorganic materials, it is worth reconsidering the exclusivity of sentience. Here, we argue that sentience, like other cognitive functions, is likely multiply realized within diverse substrates. We claim that the gatekeeping of cognitive language is made without meaningful distinction, that inferences of sentience are subject to inappropriate double standards that promote anthropocentrism, and that sentience may exist at scales of space-time that are unfamiliar to human perception. The paper provides a foundation for the establishment of principled frameworks to identify and extend ethical considerations to unconventional minds.
Background Persons with non-O and Rh-positive blood types are purported to be more susceptible to infection, including SARS-CoV-2, but there remains uncertainty about the degree to which this is so for both non-viral and viral infections. Methods We systematically reviewed Embase and PubMed from January 1st 1960 to May 31st 2022. English-language publications were selected that separately investigated the relation between ABO and/or Rh blood group and risk of SARS-CoV-2 and non-SARS-CoV-2 infection. Pooled odds ratios (ORp) and 95% confidence intervals (CI) were then generated for each. Results Non-O blood groups had a higher ORp for SARS-CoV-2 than O blood groups, both within 22 case–control studies (2.13, 95% CI 1.49- 3.04) and 15 cohort studies (1.89, 95% CI 1.56- 2.29). For non-SARS-CoV-2 viral infections, the respective ORp were 1.98 (95% CI 1.49–2.65; 4 case–control studies) and 1.87 (95% CI 1.53–2.29; 12 cohort studies). For non-viral infections, the ORp were 1.56 (95% CI 0.98–2.46; 13 case–control studies) and 2.11 (95% CI 1.67–6.67; 4 cohort studies). Rh-positive status had a higher ORp for SARS-CoV-2 infection within 6 case–control studies (13.83, 95% CI 6.18–30.96) and 6 cohort studies (19.04, 95% CI 11.63–31.17), compared to Rh-negative persons. For Rh status, non-SARS-CoV-2 infections, the ORp were 23.45 (95% CI 16.28–33.76) among 7 case–control studies, and 9.25 (95% CI 2.72–31.48) within 4 cohort studies. High measures of heterogeneity were notably observed for all analyses. Conclusions Non-O and Rh-positive blood status are each associated with a higher risk of SARS-CoV-2 infection, in addition to other viral and non-viral infections.
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6,820 members
Jonathan A Newman
  • Office of Research Services
Melody Morton Ninomiya
  • Health Sciences
Fahad Ahmad
  • Department of Psychology
Colleen Loomis
  • School of International Policy and Governance
Sumeet  Kaur Sehra
  • Department of Physics & Computer Science
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