AIM:To assess the effect of the coronavirus disease 2019(COVID-19)pandemic on the wait times and severity of surgical glaucoma cases in a single tertiary referral center in Quebec,Canada.METHODS:Preoperative severity ...AIM:To assess the effect of the coronavirus disease 2019(COVID-19)pandemic on the wait times and severity of surgical glaucoma cases in a single tertiary referral center in Quebec,Canada.METHODS:Preoperative severity data included mean visual field(VF)deficit,intraocular pressure(IOP),the number of topical glaucoma medication classes,and preoperative best corrected visual acuity(BCVA).The times from referral to procedure(referral time)and from listing date to procedure(waitlisting time)were calculated.RESULTS:This retrospective cohort study involved 181 eyes of patients undergoing glaucoma surgery from March 1 to June 30,2019(pre-pandemic period),and 201 eyes in the same timeframe in 2021(pandemic period)at Saint-Sacrement Hospital in Quebec City.There was no significant difference in the severity data of surgical glaucoma across both periods(VF deficit:P=0.48;IOP:P=0.14;BCVA:P=0.24;topical medication classes:P=0.27).The number of patients referred with oral glaucoma medication increased slightly from 45 to 70 in 2019 and 2021 respectively(P=0.08).Delay data were also comparable.Mean referral time was 122±120d in 2019 versus 144±136d in 2021(P=0.09),whereas waitlisting time before the pandemic was 43±44.5 versus 39±41.8d in 2021(P=0.13).CONCLUSION:Despite North America’s strictest pandemic restrictions,limited negative impact is observed on waitlisting delays and the severity of glaucoma cases presenting at our center.A larger subset of patients is treated with oral medications indicating a possible increase in advanced glaucoma.展开更多
In connection with the historical context of social segregation and the assimilative aim of formal education imposed on them,the Indigenous Peoples of Québec have long been excluded from higher education.Today,ev...In connection with the historical context of social segregation and the assimilative aim of formal education imposed on them,the Indigenous Peoples of Québec have long been excluded from higher education.Today,even if their graduation rates are increasing,a persistent gap with the non-Indigenous population is maintained.The data in this article are drawn from 23 interviews with students and university graduates of the First Nations of Québec,as part of a thesis in educational sciences.Our paper analyzes how these students manage to combine the contributions of Indigenous education with those of Western education by developing paths that are part of the decolonization movement of education.Their relationship to Indigenous identity and cultures clearly influences their educational background and is analyzed taking into account power relations with the dominant culture.Our paper emphasizes more particularly the relationship to studies,the adaptation to the student profession,and the balance between studies,work,and family among Indigenous students,in a context of transition from university to multiversity which contributed to the increase of Indigenous university attendance.展开更多
For most of their energy requirements, greater part of remote communities and small islands around the world rely on imported fossil fuels. The economical cost of energy is therefore very high not only due to inherent...For most of their energy requirements, greater part of remote communities and small islands around the world rely on imported fossil fuels. The economical cost of energy is therefore very high not only due to inherent cost of fuel, but also due to transportation and due to maintenance costs. One solution for saving fuel in a diesel generator is to allow the engine to operate directly in relation to the request for electrical load at variable speeds. Genset-Synchro Technology has developed an innovative variable speed?generator technology (patent pending) that allows applications where power demand varies widely to benefit from the new technology that maintains constant voltage and frequency while adjusting the generator stator speed to power demand. This paper will present an innovative approach for optimizing the energy production based from the fact that the structure that contains the stator windings of the generator is mounted on roller bearings, which allows its free rotation around the axis of the rotor, consequently stopping the stator structure from being static and aims to minimize the unit cost of electricity. Case study on application in remote area in the north of Quebec is described. A saving of 7%?-?9% on fuel consumption and greenhouse gas (GHG) under low winter ambient temperatures has been registered.展开更多
We studied late-entry commercial thinning effects on growth, yield, and regeneration in a 48-year-old jack pine(Pinus banksiana Lamb.) stand. Applied thinning intensities were 27, 32, and 47% of merchantable basal are...We studied late-entry commercial thinning effects on growth, yield, and regeneration in a 48-year-old jack pine(Pinus banksiana Lamb.) stand. Applied thinning intensities were 27, 32, and 47% of merchantable basal area(BA) excluding skidding trails. After 15 years, mean diameter at breast height of surviving trees in the 47% BA removal increased by 4.9 cm(25%) compared to the unthinned control. The 47% BA removal also increased gross merchantable volume(GMV) tree-1by 46% compared to the control. The 27% BA removal had twice as much GMV ha-1compared to the 47% BA removal after15 years. Moreover, cumulative GMV ha-1was much higher in the 27% BA removal than in the unthinned control. The highest thinning intensity produced larger trees on average, while the lowest thinning intensity maximized volume production per hectare. Maintenance of acceptable growing stock throughout the 15-year period in the 27% BA removal could provide other ecosystem functions such as biodiversity enhancement or wildlife habitat by delaying senescence. Regeneration data showed that a shift in species composition occurred in the understory. After 15 years, the understory was dominated by black spruce(Picea mariana(Mill.) B.S.P.), white birch(Betula papyrifera Marsh.), and trembling aspen(Populus tremuloides Michx.). If regenerating jack pine is an objective after final overstory removal, additional efforts will be needed to re-establish this species.展开更多
Vertical orthogonal joints are a common feature in shallow crustal rocks.There are several competing theories for their formation despite the ubiquity.We examined the exceptional exposures of orthogonal joints in flat...Vertical orthogonal joints are a common feature in shallow crustal rocks.There are several competing theories for their formation despite the ubiquity.We examined the exceptional exposures of orthogonal joints in flat-lying Ordovician limestone beds from the Havre-Saint-Pierre Region in Quebec,Canada(north shore of Saint-Lawrence River)to test conceptual models of joint formation in a natural setting.In the region,the spacing of cross-joints is consistently larger than the spacing of systematic joints by a factor of 1.5 approximately.The joint-spacing-to-bed-thickness ratios(s/t)are much larger in these beds(s/t=4.3 for systematic joints,and 6.4 for cross-joints)than those in higher strained strata along the south shore of the Saint-Lawrence River(s/t=1),highlighting the effect of tectonic strain in decreasing fracture spacing and block size.The high values of s/t indicate that cross-joint formation was unlikely caused by a switch from compression to tension once a critical s/t ratio for systematic joints was reached(as hypothesized in previous studies).We proposed a new model for the formation of orthogonal joint systems where the principal stress axes locally switch during the formation of systematic fractures.The presence of ladder-shaped orthogonal joints suggests a state of effective stress withσ_(1)^(∗)≫0>σ_(2)^(∗)>σ_(3)^(∗)and whereσ_(2)^(∗)-σ_(3)^(∗)is within the range of fracture strength variability at the time of fracture.This research provides a new mechanical model for the formation of orthogonal joint systems and cuboidal blocks.展开更多
The “ionome”, or plant elemental signature, is the elemental composition of an organisms, that may vary with genotypic traits and phenotypic plasticity. Cloudberry (Rubus chamaemorus L.) is a circumboreal wild berry...The “ionome”, or plant elemental signature, is the elemental composition of an organisms, that may vary with genotypic traits and phenotypic plasticity. Cloudberry (Rubus chamaemorus L.) is a circumboreal wild berry naturally growing in oligotrophic oceanic bogs ofQuebecandLabrador. Our objective was to relate cloudberry stand productivity to the ionomes of female ramets and explore the cause of nutrient imbalance in low-performing stands. We analyzed 13 elements in female ramets collected in 86 natural sites where crop productivity varied widely. We computed orthogonally arranged balances reflecting plant stoichiometric rules and soil biogeochemistry. Balances were expressed as isometric log ratios (ilr) between ad hoc sub-compositions. Balances were synthesized into a Mahalanobis distance optimized based on receiving operating characteristics (ROC). The critical Mahalanobis distance was found to be 5.29 for cutoff berry yield of3.8 g.m-2 with test performance of 0.88, as measured by the area under the ROC curve. Although past research on cloudberry focused mainly on the N/P ratio, this exploratory mineral balance analysis indicated that imbalance in the [P,N | S,C] and [Al | Nutrients] partitions appeared to be the factors limiting the most cloudberry productivity in the bogs. Some highly productive stands showed relatively high C fixation and K use efficiency. Due to the complexity of interactions, diagnosis should be conducted computing first a global imbalance index (Mahalanobis distance), then examining in the balance domain binary partitions departing most from reference, and finally appreciating relative shortage, sufficiency or excess of elements in the concentration domain.展开更多
Background and Objectives: Asthma is a heterogeneous disease where patient severity can be classified according to various models based on numerous variables. Large collections of well-phenotyped subjects are needed t...Background and Objectives: Asthma is a heterogeneous disease where patient severity can be classified according to various models based on numerous variables. Large collections of well-phenotyped subjects are needed to find distinct clusters of patients for personalized medicine and future genetic studies. The objective of this study is to describe the collection of the Quebec City Case-Control Asthma Cohort and to identify homogeneous subgroups of asthma patients based on clinical characteristics. Methods: This cohort is part of an ongoing project initiated in 2007 to elucidate the genetic basis of asthma. All subjects are randomly recruited at the same site following advertisements. Subjects are unrelated French Canadian white adults 18 years of age or older. Each participant underwent a spirometry, methacholine challenge, and allergy skin-prick tests. Blood was collected for DNA, cell counts and total serum IgE measurements. So far, 982 subjects have been recruited and classified as cases (n = 566) or controls (n = 416). We performed factor and cluster analyses on collected phenotypes from this set to identify subgroups of phenotypically similar asthmatic patients. Results: Factor analysis with 13 variables led to the selection of five factors: lung function, numbers of allergens, blood eosinophil percentage, smoking status and age. K-means cluster analysis on the reduced dataset produced four significantly different groups with the following characteristics: smoking history, low atopy and low lung function, high atopy, and young non-smoking with average atopy. Conclusions: The Quebec City Case-Control Asthma Cohort is a new resource for local and collaborative clinical and genetic research on asthma. This new collection reveals distinct multivariate phenotypes of adult asthma that are likely to be important for future genetic studies and targeted therapies.展开更多
Background:Sharing biological material and clinical data from patients with uveal melanoma.Methods:Uveal melanoma is the most common intraocular malignancy in the adult population.Because uveal melanoma is primarily a...Background:Sharing biological material and clinical data from patients with uveal melanoma.Methods:Uveal melanoma is the most common intraocular malignancy in the adult population.Because uveal melanoma is primarily a sporadic cancer and familial cases are rare,it is difficult to prevent or detect it.Despite effective treatment of ocular tumors,more than 50%of patients develop incurable liver metastases mainly in the 5-10 years following the detection of the primary tumor.This cancer is relatively rare and the obtained biopsies are very small.About 20 samples are taken each year in Quebec.This provincial infrastructure is made of biological material from donors with uveal melanoma and a large clinical database.Collected tumor biopsies are used for culturing cell lines and the creation of a DNA/RNA library used for genomic and genetic studies.Results:This infrastructure plays an important role in the achievement of various research programs for a better understanding of genetic and environmental factors involved in the development of melanoma and the spread of metastasis.It allows collaboration with other researchers at a provincial,national and international level in order to make progress in basic and clinical research on uveal melanoma.Conclusions:The biological material and clinical data of this infrastructure are available upon request to VHRN members whose research project was approved by the ethics committee of the institution.展开更多
Lichen woodlands (LW) located in the closed-crown boreal forest are not a successional stage moving towards a closed black spruce feathermoss stand (FM), but an alternative stable state, due to their previous forest h...Lichen woodlands (LW) located in the closed-crown boreal forest are not a successional stage moving towards a closed black spruce feathermoss stand (FM), but an alternative stable state, due to their previous forest history, and the occurrence of LWs located nearby closed-crown FM stands. Therefore, afforestation in those LWs through site preparation and plantation could shift back LW into FM stands. We implemented an experimental design with different combinations of silvicultural treatments in both site types (LW, FM). We monitored the evolution of plant diversity and the physiology of three bio-indicators (Picea mariana, Kalmia angustifolia, Rhododendron groenlandicum) in different microsites created by the silvicultural treatments. The return to the initial composition was noticed only two years after treatments, especially in the LW stands, thus indicating a higher level of early ecosystem resilience in LWs compared to FM stands. Mean species cover, especially in the FM stands, decreased the most in the skid trails created by logging, probably due to a lack of acclimation of bryophytes to open stand conditions. Conversely, ericaceous shrubs and lichens found in the LWs were already acclimated to open stand conditions, which give to LWs a restructuring advantage compared to FM plant communities after silvicultural treatments. Overall, FM and LW short-term resilience was similar, indicating equally efficient ecosystem reorganization in both stands. The comparable early resilience in managed LW and FM stands, in terms of plant biodiversity, contradicts the presumed fragility of LW stands, especially in this case where LWs are assumed to be an alternative stable state created by compound disturbances. Silvicultural treatments maintained the functional group diversity in LWs, a key element for ecosystem resilience. Therefore, this study support the idea that plantation following site preparation in LWs could be a valuable management strategy to reach several objectives, such as increasing forest carbon sinks.展开更多
This study numerically investigates the thermo-poromechanical effects in a Canadian geothermal reservoir caused by long-term fluid production and injection.Using finite element modeling,it explores pore pressure diffu...This study numerically investigates the thermo-poromechanical effects in a Canadian geothermal reservoir caused by long-term fluid production and injection.Using finite element modeling,it explores pore pressure diffusion and thermal dynamics,incorporating both the geological structure of the rock mass and faults.The simulations utilize the IAPWS(International Association for the Properties of Water and Steam)equations to model fluid density and viscosity,ensuring realistic representations of heterogeneous pressure fields.The system replicates a doublet configuration within a faulted zone,featuring two hydraulically stimulated fractures.The primary aim is to assess the likelihood of fault reactivation under varying in-situ stress conditions over a 100-year geothermal operation.Results show that stress distribution is largely influenced by thermal stresses along the fluid circulation pathway,with fluid velocity and temperature gradients affecting reservoir stability.Minimal pore pressure changes highlight the dominant role of thermal stresses in controlling fault behavior.The analysis indicates no potential for fault reactivation,as slip tendency values remain below the critical threshold,even when accounting for reduced mechanical properties using the Hoek-Brown criterion.Thermal effects continue to influence the surrounding rock throughout the operational period,suggesting that the reservoir maintains mechanical stability conducive to sustained geothermal production and injection.These findings provide valuable insights into the long-term safety and behavior of geothermal reservoirs,offering important implications for future geothermal energy development and management strategies.展开更多
Mesenchymal stem cells(MSCs)are multipotent adult stem cells of mesodermal origin that can be isolated from various tissues,including bone marrow,tooth pulp,adipose tissue,and umbilical cord.MSCs have gained significa...Mesenchymal stem cells(MSCs)are multipotent adult stem cells of mesodermal origin that can be isolated from various tissues,including bone marrow,tooth pulp,adipose tissue,and umbilical cord.MSCs have gained significant attention in regenerative medicine due to their ability to modulate the immune system and favor tissue repair.MSCs enrich the medium in which they are cultivated with a broad range of bioactive molecules,including growth factors,cytokines,chemokines,enzymes,nucleic acids,and extracellular vesicles that collectively compose the MSC secretome.An increasing number of pre-clinical studies suggest that delivering in vivo an MSC-conditioned medium(i.e.,the medium collected from MSC cultures after at least 3 days of exposure)exerts neuroprotective and anti-inflammatory effects in a variety of neurological conditions.展开更多
[Objective]Traditional structural geology textbooks often provide outdated treatments of joints and veins,failing to reflect the significant advances made in the past three decades.This review seeks to address part of...[Objective]Traditional structural geology textbooks often provide outdated treatments of joints and veins,failing to reflect the significant advances made in the past three decades.This review seeks to address part of this gap by highlighting the significance of barren joints and veins in reconstructing both the directions and magnitudes of geological paleostresses.[Conclusion]Conjugate shear joints not only indicate the orientation of the three effective principal stresses but also imply differential stresses at least four times greater than the tensile strength of the brittle host rock.Exfoliation joints form under stress states ofσ_(1)≈σ_(2)>0>σ_(3),whereas polygonal columnar joints in sedimentary rocks reflectσ_(1)^(*)>>σ_(2)^(*)=σ_(3)^(*),allowing the tensile strength of rocks to be estimated.Tensile joints in brittle strong beds interlayered with ductile soft layers are primarily driven by tensile stresses transferred from interfacial shear stresses between the hard and soft layers,with joint saturation mainly controlled by tectonic strain.Under natural strain-rate conditions,the Weibull modulus and tensile strength of the strong layers,as well as the shear-flow strength of the ductile layers,can be inferred from the nonlinear relationship between joint spacing and bed thickness.Ladder-like orthogonal joints,which form under a stress state ofσ_(1)^(*)>>σ_(2)^(*)>σ_(3)^(*),divide strata into blocky units and,after weathering and erosion,give rise to characteristic castle-and tower-like landforms.Veins,as mineral-filled joints,provide spacing and thickness data that allow estimates of layer strain.Moreover,the nonlinear relationship between vein spacing and bed thickness permits quantification of the extent to which mineral precipitation restores the tensile strength of rock beds.The absence of ladder-like orthogonal veins is attributed to this strength recovery.[Significance]Collectively,these observations demonstrate the critical role of joints and veins in constraining both the magnitudes and orientations of geological paleostress fields.展开更多
This article revisits the concept of epistemological rupture by questioning the stark division between scientific and non-scientific thought. Drawing on the theory of representation, it contends that both forms of kno...This article revisits the concept of epistemological rupture by questioning the stark division between scientific and non-scientific thought. Drawing on the theory of representation, it contends that both forms of knowledge are socially constructed, moulded by communication, norms and group dynamics. Rather than labelling non-scientific thought as flawed or regressive, the discussion shows how decontextualization and recontextualization processes apply equally to everyday ‘natural' knowledge and formal science,exposing the social and historical contingencies shaping concepts. Consequently, rupture appears less a sudden break than a gradual threshold reached through dialectical transformations in cognition and society. Rather than conferring total superiority on science, ruptures highlight how certain discourses gain legitimacy while others become ‘non-knowledge'. The article concludes that science's dominance reflects broader power relationships and evolving modes of production and validation. By situating epistemological rupture within these processes, it illuminates how different knowledge forms coexist, evolve and sometimes conflict in stratified social fields—ultimately challenging a simplistic binary between scientific progress and supposedly primitive or natural thought. This viewpoint opens new possibilities for examining the shifting boundaries between rational explanations and the shared beliefs shaping collective reality and daily life.展开更多
Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are...Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are incomplete and spare supraspinal pathways,especially those located within the peripheral white matter of the spinal cord,which includes reticulospinal pathways originating from the medullary reticular formation.Whereas there is abundant literature about the motor cortex,its corticospinal pathway,and its capacity to modulate functional recovery after SCI,less is known about the medullary reticular formation and its reticulospinal pathway.展开更多
Viral diseases are an important threat to crop yield,as they are responsible for losses greater than US$30 billion annually.Thus,understanding the dynamics of virus propagation within plant cells is essential for devi...Viral diseases are an important threat to crop yield,as they are responsible for losses greater than US$30 billion annually.Thus,understanding the dynamics of virus propagation within plant cells is essential for devising effective control strategies.However,viruses are complex to propagate and quantify.Existing methodologies for viral quantification tend to be expensive and time-consuming.Here,we present a rapid cost-effective approach to quantify viral propagation using an engineered virus expressing a fluorescent reporter.Using a microplate reader,we measured viral protein levels and we validated our findings through comparison by western blot analysis of viral coat protein,the most common approach to quantify viral titer.Our proposed methodology provides a practical and accessible approach to studying virus-host interactions and could contribute to enhancing our understanding of plant virology.展开更多
The active ingredient(a.i.)glyphosate is frequently detected in waterways at relatively high concentrations,posing a risk to aquatic organisms including freshwater mussels,North America’s most endangered animal group...The active ingredient(a.i.)glyphosate is frequently detected in waterways at relatively high concentrations,posing a risk to aquatic organisms including freshwater mussels,North America’s most endangered animal group.This research aims to evaluate for the first time the effect of a glyphosate-based herbicide on a freshwater mussel(Unionid)using a battery of biomarkers.Themussel Elliptio complanata was exposed for 21 days to CreditR Xtreme(at 0,50,100,and 150μg/L a.i.of glyphosate).An integrated biomarker response(IBRv2)was used to visualize the overall impact of each glyphosate-based herbicide concentration on mussels’health conditions.The biomarker results showed that glyphosate(used at 100μg/L and 150μg/L)induced lipid peroxidation in the gills and digestive gland and inhibited acetylcholinesterase in the foot and gills,indicating oxidative damage and neurotoxicity.Other biomarkerswere influenced at the lowest concentration of glyphosate tested(50μg/L):lipids(decrease),triglycerides(increase)and,to a lesser extent,vitellogenin(decrease).For the latter biomarkers,the sexeswere not affected similarly,and theywere only sensitive at 50μg/L,only females showed a trend toward a decrease for vitellogenin and a decrease for lipids.Using IBRv2,we found a clear discrimination between concentrations,and the index values increased with glyphosate concentration,attesting to the deterioration in biomarker-defined mussel health when exposed to Credit® Xtreme at realistic glyphosate concentrations in agricultural rivers.This study shows that glyphosate-based herbicides can alter neurological function,induce oxidative damage,and selectively modify the E.complanata metabolism at relatively low concentrations.展开更多
Febrile infants are at greater risk of invasive bacterial infections (IBI),which include bacterial meningitis and bacteremia.Although bacterial meningitis is uncommon,^([1-2])it remains a concern for clinicians treati...Febrile infants are at greater risk of invasive bacterial infections (IBI),which include bacterial meningitis and bacteremia.Although bacterial meningitis is uncommon,^([1-2])it remains a concern for clinicians treating infants younger than 90 d.Guidelines for investigating fever without a source(meaning without an apparent source of infection,or of nonobvious origin) are numerous around the world but remain conflicting,particularly on whether to perform a lumbar puncture for cerebrospinal fluid (CSF) analysis in infants older than 22 d and hence at lower risk than younger infants.展开更多
In this study,two series of foams based on tannic acid(TA),furfuryl alcohol(FA),soybean protein isolate(SPI),and casein(CA),namely TA–FA–SPI(TS series)and TA–FA–CA(TC series)were developed,and their properties wer...In this study,two series of foams based on tannic acid(TA),furfuryl alcohol(FA),soybean protein isolate(SPI),and casein(CA),namely TA–FA–SPI(TS series)and TA–FA–CA(TC series)were developed,and their properties were enhanced by adding poplar fibers(WF).From the samples produced,a complete set of characterization was performed including possible crosslinking reactions,morphology,mechanical properties,flame retardancy,thermal insulation and thermal stability.Fourier-transform infrared spectroscopy(FTIR)revealed possible covalent crosslinking among the components and hydrogen bonding between WF and the matrix.Viscosity results indicated that lower prepolymer viscosity led to lower apparent density,while WF addition reduced even more the density.Mechanical tests showed that the maximum compressive strengths were good,while WF improved the compressive strength by up to 56%.Scanning electron microscopy(SEM)showed uniform cell structures,but small open pores were observed.Two-dimensional(2D)CT scan images confirmed the good compatibility between WF and the matrix,with low anisotropy in the material.Friability tests indicated that WF decreased the pulverization ratio of the materials by up to 42%.Thermogravimetric analysis(TGA)showed good thermal stability of the materials up to 328°C.Vertical burning tests showed that the materials were self-extinguishing without residue(dripping).The lowest thermal conductivity was 0.04 W/m·K.These results suggest that these novel formaldehyde-free,high biomass content(95%–96%)foams and composite foams have high potential to replace traditional phenolic foams(PF)in applications such as construction,transportation,packaging,and thermal insulation.展开更多
Atomically dispersed metal site(ADMS)materials have emerged as a promising class of materials for electrocatalysis reactions in the field of energy conversion.Characterized by individual metal atoms dispersed on suita...Atomically dispersed metal site(ADMS)materials have emerged as a promising class of materials for electrocatalysis reactions in the field of energy conversion.Characterized by individual metal atoms dispersed on suitable supports,ADMS materials provide unique catalytic sites with highly tunable electronic structures.This review summarizes recent advancements in the field,with a focus on the critical roles of support materials,coordination environments,and the mechanisms underlying catalytic activity at the atomic level.First,commonly used density functional theory(DFT)simulations are reviewed,emphasizing their pivotal role in elucidating reaction mechanisms and predicting the behavior of ADMS in electrochemical reactions for hydrogen energy utilization.Then,advancements in ADMS for half-cell electrochemical reactions,including oxygen evolution reaction,hydrogen evolution reaction,and oxygen reduction reaction,as well as their applications in fuel cells and water splitting,are summarized.Finally,the challenges and future prospects of ADMS are discussed.This review underscores the transformative potential of ADMS in electrocatalysis,paving the way for innovative and sustainable energy conversion technologies.展开更多
Effective forest regeneration is essential for sustainable forestry practices.In Sweden,mechanical site preparation and manual planting is the dominating method,but sourcing labour for the physically demanding work is...Effective forest regeneration is essential for sustainable forestry practices.In Sweden,mechanical site preparation and manual planting is the dominating method,but sourcing labour for the physically demanding work is difficult.An autonomous scarifying and planting system(Autoplant)could meet the requirements of the forest industry and,for this,a tool for regeneration planning and routing is needed.The tool,Pathfinder,plans the regeneration and routes based on the harvested production(hpr)files,soil moisture and parent material maps,no-go areas(for culture or nature conservation),digital elevation models(DEM),and machine data(e.g.,working width,critical slope,time taken for different turn angles).The overall planting solution is either a set of capacity constrained routes or a continuous route and could be used for any planting machine as well as for traditional scarifiers as disc trenchers or mounders pulled by forwarders.Pathfinder was tested on eleven regeneration areas throughout Sweden,both with continuous routes and routes based on a carrying capacity of 1500 seedlings.The net operation area,species and seedling density suggestions were deemed relevant by expert judgement in the field.The routes provided by Pathfinder were compared with solutions given by two experienced drivers and a third solution based on the actual soil scarification at the site.Total driving distance did not differ significantly between the suggestions,but Pathfinder included less side-slope driving on steep slopes(≥27%or 15°)and medium slopes(15–27%).The chosen threshold value for steep slopes(where side-slope driving should be avoided)affects the routing,and a lower threshold means more turning and longer driving distance.Pathfinder is not only a tool for routing of planting machines,but also helps in planning of traditional regeneration by providing a more correct net area and tree species suggestions based on the growth of the previous stand.It also diminishes the risk of severe soil disturbance by excluding the wettest area in the planning.展开更多
文摘AIM:To assess the effect of the coronavirus disease 2019(COVID-19)pandemic on the wait times and severity of surgical glaucoma cases in a single tertiary referral center in Quebec,Canada.METHODS:Preoperative severity data included mean visual field(VF)deficit,intraocular pressure(IOP),the number of topical glaucoma medication classes,and preoperative best corrected visual acuity(BCVA).The times from referral to procedure(referral time)and from listing date to procedure(waitlisting time)were calculated.RESULTS:This retrospective cohort study involved 181 eyes of patients undergoing glaucoma surgery from March 1 to June 30,2019(pre-pandemic period),and 201 eyes in the same timeframe in 2021(pandemic period)at Saint-Sacrement Hospital in Quebec City.There was no significant difference in the severity data of surgical glaucoma across both periods(VF deficit:P=0.48;IOP:P=0.14;BCVA:P=0.24;topical medication classes:P=0.27).The number of patients referred with oral glaucoma medication increased slightly from 45 to 70 in 2019 and 2021 respectively(P=0.08).Delay data were also comparable.Mean referral time was 122±120d in 2019 versus 144±136d in 2021(P=0.09),whereas waitlisting time before the pandemic was 43±44.5 versus 39±41.8d in 2021(P=0.13).CONCLUSION:Despite North America’s strictest pandemic restrictions,limited negative impact is observed on waitlisting delays and the severity of glaucoma cases presenting at our center.A larger subset of patients is treated with oral medications indicating a possible increase in advanced glaucoma.
文摘In connection with the historical context of social segregation and the assimilative aim of formal education imposed on them,the Indigenous Peoples of Québec have long been excluded from higher education.Today,even if their graduation rates are increasing,a persistent gap with the non-Indigenous population is maintained.The data in this article are drawn from 23 interviews with students and university graduates of the First Nations of Québec,as part of a thesis in educational sciences.Our paper analyzes how these students manage to combine the contributions of Indigenous education with those of Western education by developing paths that are part of the decolonization movement of education.Their relationship to Indigenous identity and cultures clearly influences their educational background and is analyzed taking into account power relations with the dominant culture.Our paper emphasizes more particularly the relationship to studies,the adaptation to the student profession,and the balance between studies,work,and family among Indigenous students,in a context of transition from university to multiversity which contributed to the increase of Indigenous university attendance.
文摘For most of their energy requirements, greater part of remote communities and small islands around the world rely on imported fossil fuels. The economical cost of energy is therefore very high not only due to inherent cost of fuel, but also due to transportation and due to maintenance costs. One solution for saving fuel in a diesel generator is to allow the engine to operate directly in relation to the request for electrical load at variable speeds. Genset-Synchro Technology has developed an innovative variable speed?generator technology (patent pending) that allows applications where power demand varies widely to benefit from the new technology that maintains constant voltage and frequency while adjusting the generator stator speed to power demand. This paper will present an innovative approach for optimizing the energy production based from the fact that the structure that contains the stator windings of the generator is mounted on roller bearings, which allows its free rotation around the axis of the rotor, consequently stopping the stator structure from being static and aims to minimize the unit cost of electricity. Case study on application in remote area in the north of Quebec is described. A saving of 7%?-?9% on fuel consumption and greenhouse gas (GHG) under low winter ambient temperatures has been registered.
基金supported by the grant from Forest Research Branch of the Québec Ministry of Forests,Parks,and Wildlife(No.142332012)
文摘We studied late-entry commercial thinning effects on growth, yield, and regeneration in a 48-year-old jack pine(Pinus banksiana Lamb.) stand. Applied thinning intensities were 27, 32, and 47% of merchantable basal area(BA) excluding skidding trails. After 15 years, mean diameter at breast height of surviving trees in the 47% BA removal increased by 4.9 cm(25%) compared to the unthinned control. The 47% BA removal also increased gross merchantable volume(GMV) tree-1by 46% compared to the control. The 27% BA removal had twice as much GMV ha-1compared to the 47% BA removal after15 years. Moreover, cumulative GMV ha-1was much higher in the 27% BA removal than in the unthinned control. The highest thinning intensity produced larger trees on average, while the lowest thinning intensity maximized volume production per hectare. Maintenance of acceptable growing stock throughout the 15-year period in the 27% BA removal could provide other ecosystem functions such as biodiversity enhancement or wildlife habitat by delaying senescence. Regeneration data showed that a shift in species composition occurred in the understory. After 15 years, the understory was dominated by black spruce(Picea mariana(Mill.) B.S.P.), white birch(Betula papyrifera Marsh.), and trembling aspen(Populus tremuloides Michx.). If regenerating jack pine is an objective after final overstory removal, additional efforts will be needed to re-establish this species.
基金The authors express their gratitude to the Natural Sciences and Engineering Research Council of Canada for financial support through a Discovery Grant(Grant No.06408).
文摘Vertical orthogonal joints are a common feature in shallow crustal rocks.There are several competing theories for their formation despite the ubiquity.We examined the exceptional exposures of orthogonal joints in flat-lying Ordovician limestone beds from the Havre-Saint-Pierre Region in Quebec,Canada(north shore of Saint-Lawrence River)to test conceptual models of joint formation in a natural setting.In the region,the spacing of cross-joints is consistently larger than the spacing of systematic joints by a factor of 1.5 approximately.The joint-spacing-to-bed-thickness ratios(s/t)are much larger in these beds(s/t=4.3 for systematic joints,and 6.4 for cross-joints)than those in higher strained strata along the south shore of the Saint-Lawrence River(s/t=1),highlighting the effect of tectonic strain in decreasing fracture spacing and block size.The high values of s/t indicate that cross-joint formation was unlikely caused by a switch from compression to tension once a critical s/t ratio for systematic joints was reached(as hypothesized in previous studies).We proposed a new model for the formation of orthogonal joint systems where the principal stress axes locally switch during the formation of systematic fractures.The presence of ladder-shaped orthogonal joints suggests a state of effective stress withσ_(1)^(∗)≫0>σ_(2)^(∗)>σ_(3)^(∗)and whereσ_(2)^(∗)-σ_(3)^(∗)is within the range of fracture strength variability at the time of fracture.This research provides a new mechanical model for the formation of orthogonal joint systems and cuboidal blocks.
文摘The “ionome”, or plant elemental signature, is the elemental composition of an organisms, that may vary with genotypic traits and phenotypic plasticity. Cloudberry (Rubus chamaemorus L.) is a circumboreal wild berry naturally growing in oligotrophic oceanic bogs ofQuebecandLabrador. Our objective was to relate cloudberry stand productivity to the ionomes of female ramets and explore the cause of nutrient imbalance in low-performing stands. We analyzed 13 elements in female ramets collected in 86 natural sites where crop productivity varied widely. We computed orthogonally arranged balances reflecting plant stoichiometric rules and soil biogeochemistry. Balances were expressed as isometric log ratios (ilr) between ad hoc sub-compositions. Balances were synthesized into a Mahalanobis distance optimized based on receiving operating characteristics (ROC). The critical Mahalanobis distance was found to be 5.29 for cutoff berry yield of3.8 g.m-2 with test performance of 0.88, as measured by the area under the ROC curve. Although past research on cloudberry focused mainly on the N/P ratio, this exploratory mineral balance analysis indicated that imbalance in the [P,N | S,C] and [Al | Nutrients] partitions appeared to be the factors limiting the most cloudberry productivity in the bogs. Some highly productive stands showed relatively high C fixation and K use efficiency. Due to the complexity of interactions, diagnosis should be conducted computing first a global imbalance index (Mahalanobis distance), then examining in the balance domain binary partitions departing most from reference, and finally appreciating relative shortage, sufficiency or excess of elements in the concentration domain.
文摘Background and Objectives: Asthma is a heterogeneous disease where patient severity can be classified according to various models based on numerous variables. Large collections of well-phenotyped subjects are needed to find distinct clusters of patients for personalized medicine and future genetic studies. The objective of this study is to describe the collection of the Quebec City Case-Control Asthma Cohort and to identify homogeneous subgroups of asthma patients based on clinical characteristics. Methods: This cohort is part of an ongoing project initiated in 2007 to elucidate the genetic basis of asthma. All subjects are randomly recruited at the same site following advertisements. Subjects are unrelated French Canadian white adults 18 years of age or older. Each participant underwent a spirometry, methacholine challenge, and allergy skin-prick tests. Blood was collected for DNA, cell counts and total serum IgE measurements. So far, 982 subjects have been recruited and classified as cases (n = 566) or controls (n = 416). We performed factor and cluster analyses on collected phenotypes from this set to identify subgroups of phenotypically similar asthmatic patients. Results: Factor analysis with 13 variables led to the selection of five factors: lung function, numbers of allergens, blood eosinophil percentage, smoking status and age. K-means cluster analysis on the reduced dataset produced four significantly different groups with the following characteristics: smoking history, low atopy and low lung function, high atopy, and young non-smoking with average atopy. Conclusions: The Quebec City Case-Control Asthma Cohort is a new resource for local and collaborative clinical and genetic research on asthma. This new collection reveals distinct multivariate phenotypes of adult asthma that are likely to be important for future genetic studies and targeted therapies.
文摘Background:Sharing biological material and clinical data from patients with uveal melanoma.Methods:Uveal melanoma is the most common intraocular malignancy in the adult population.Because uveal melanoma is primarily a sporadic cancer and familial cases are rare,it is difficult to prevent or detect it.Despite effective treatment of ocular tumors,more than 50%of patients develop incurable liver metastases mainly in the 5-10 years following the detection of the primary tumor.This cancer is relatively rare and the obtained biopsies are very small.About 20 samples are taken each year in Quebec.This provincial infrastructure is made of biological material from donors with uveal melanoma and a large clinical database.Collected tumor biopsies are used for culturing cell lines and the creation of a DNA/RNA library used for genomic and genetic studies.Results:This infrastructure plays an important role in the achievement of various research programs for a better understanding of genetic and environmental factors involved in the development of melanoma and the spread of metastasis.It allows collaboration with other researchers at a provincial,national and international level in order to make progress in basic and clinical research on uveal melanoma.Conclusions:The biological material and clinical data of this infrastructure are available upon request to VHRN members whose research project was approved by the ethics committee of the institution.
基金funded by a Fonds de Recherche pour la Nature et des Technologies du Gouvernement du Québec(FQRNT)grant to D.Lord,and the Carbone boréal project.
文摘Lichen woodlands (LW) located in the closed-crown boreal forest are not a successional stage moving towards a closed black spruce feathermoss stand (FM), but an alternative stable state, due to their previous forest history, and the occurrence of LWs located nearby closed-crown FM stands. Therefore, afforestation in those LWs through site preparation and plantation could shift back LW into FM stands. We implemented an experimental design with different combinations of silvicultural treatments in both site types (LW, FM). We monitored the evolution of plant diversity and the physiology of three bio-indicators (Picea mariana, Kalmia angustifolia, Rhododendron groenlandicum) in different microsites created by the silvicultural treatments. The return to the initial composition was noticed only two years after treatments, especially in the LW stands, thus indicating a higher level of early ecosystem resilience in LWs compared to FM stands. Mean species cover, especially in the FM stands, decreased the most in the skid trails created by logging, probably due to a lack of acclimation of bryophytes to open stand conditions. Conversely, ericaceous shrubs and lichens found in the LWs were already acclimated to open stand conditions, which give to LWs a restructuring advantage compared to FM plant communities after silvicultural treatments. Overall, FM and LW short-term resilience was similar, indicating equally efficient ecosystem reorganization in both stands. The comparable early resilience in managed LW and FM stands, in terms of plant biodiversity, contradicts the presumed fragility of LW stands, especially in this case where LWs are assumed to be an alternative stable state created by compound disturbances. Silvicultural treatments maintained the functional group diversity in LWs, a key element for ecosystem resilience. Therefore, this study support the idea that plantation following site preparation in LWs could be a valuable management strategy to reach several objectives, such as increasing forest carbon sinks.
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant Canada(NO.RGPIN-2024-05104).
文摘This study numerically investigates the thermo-poromechanical effects in a Canadian geothermal reservoir caused by long-term fluid production and injection.Using finite element modeling,it explores pore pressure diffusion and thermal dynamics,incorporating both the geological structure of the rock mass and faults.The simulations utilize the IAPWS(International Association for the Properties of Water and Steam)equations to model fluid density and viscosity,ensuring realistic representations of heterogeneous pressure fields.The system replicates a doublet configuration within a faulted zone,featuring two hydraulically stimulated fractures.The primary aim is to assess the likelihood of fault reactivation under varying in-situ stress conditions over a 100-year geothermal operation.Results show that stress distribution is largely influenced by thermal stresses along the fluid circulation pathway,with fluid velocity and temperature gradients affecting reservoir stability.Minimal pore pressure changes highlight the dominant role of thermal stresses in controlling fault behavior.The analysis indicates no potential for fault reactivation,as slip tendency values remain below the critical threshold,even when accounting for reduced mechanical properties using the Hoek-Brown criterion.Thermal effects continue to influence the surrounding rock throughout the operational period,suggesting that the reservoir maintains mechanical stability conducive to sustained geothermal production and injection.These findings provide valuable insights into the long-term safety and behavior of geothermal reservoirs,offering important implications for future geothermal energy development and management strategies.
基金supported by the National Centre for the Replacement Refinement & Reduction of Animals in Research Crack It solution “Neuroinflammation and nociception in a dish”(https://nc3rs.org.uk/crackit/news/new-solutionneuroinflammation-and-nociception-dish) fund(to AM)。
文摘Mesenchymal stem cells(MSCs)are multipotent adult stem cells of mesodermal origin that can be isolated from various tissues,including bone marrow,tooth pulp,adipose tissue,and umbilical cord.MSCs have gained significant attention in regenerative medicine due to their ability to modulate the immune system and favor tissue repair.MSCs enrich the medium in which they are cultivated with a broad range of bioactive molecules,including growth factors,cytokines,chemokines,enzymes,nucleic acids,and extracellular vesicles that collectively compose the MSC secretome.An increasing number of pre-clinical studies suggest that delivering in vivo an MSC-conditioned medium(i.e.,the medium collected from MSC cultures after at least 3 days of exposure)exerts neuroprotective and anti-inflammatory effects in a variety of neurological conditions.
文摘[Objective]Traditional structural geology textbooks often provide outdated treatments of joints and veins,failing to reflect the significant advances made in the past three decades.This review seeks to address part of this gap by highlighting the significance of barren joints and veins in reconstructing both the directions and magnitudes of geological paleostresses.[Conclusion]Conjugate shear joints not only indicate the orientation of the three effective principal stresses but also imply differential stresses at least four times greater than the tensile strength of the brittle host rock.Exfoliation joints form under stress states ofσ_(1)≈σ_(2)>0>σ_(3),whereas polygonal columnar joints in sedimentary rocks reflectσ_(1)^(*)>>σ_(2)^(*)=σ_(3)^(*),allowing the tensile strength of rocks to be estimated.Tensile joints in brittle strong beds interlayered with ductile soft layers are primarily driven by tensile stresses transferred from interfacial shear stresses between the hard and soft layers,with joint saturation mainly controlled by tectonic strain.Under natural strain-rate conditions,the Weibull modulus and tensile strength of the strong layers,as well as the shear-flow strength of the ductile layers,can be inferred from the nonlinear relationship between joint spacing and bed thickness.Ladder-like orthogonal joints,which form under a stress state ofσ_(1)^(*)>>σ_(2)^(*)>σ_(3)^(*),divide strata into blocky units and,after weathering and erosion,give rise to characteristic castle-and tower-like landforms.Veins,as mineral-filled joints,provide spacing and thickness data that allow estimates of layer strain.Moreover,the nonlinear relationship between vein spacing and bed thickness permits quantification of the extent to which mineral precipitation restores the tensile strength of rock beds.The absence of ladder-like orthogonal veins is attributed to this strength recovery.[Significance]Collectively,these observations demonstrate the critical role of joints and veins in constraining both the magnitudes and orientations of geological paleostress fields.
文摘This article revisits the concept of epistemological rupture by questioning the stark division between scientific and non-scientific thought. Drawing on the theory of representation, it contends that both forms of knowledge are socially constructed, moulded by communication, norms and group dynamics. Rather than labelling non-scientific thought as flawed or regressive, the discussion shows how decontextualization and recontextualization processes apply equally to everyday ‘natural' knowledge and formal science,exposing the social and historical contingencies shaping concepts. Consequently, rupture appears less a sudden break than a gradual threshold reached through dialectical transformations in cognition and society. Rather than conferring total superiority on science, ruptures highlight how certain discourses gain legitimacy while others become ‘non-knowledge'. The article concludes that science's dominance reflects broader power relationships and evolving modes of production and validation. By situating epistemological rupture within these processes, it illuminates how different knowledge forms coexist, evolve and sometimes conflict in stratified social fields—ultimately challenging a simplistic binary between scientific progress and supposedly primitive or natural thought. This viewpoint opens new possibilities for examining the shifting boundaries between rational explanations and the shared beliefs shaping collective reality and daily life.
基金supported by Craig H.Neilsen Foundation,Wings for Life Foundation,Canadian Institutes of Health Research,and Fonds de Recherche Québec-Santé(to FB).
文摘Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are incomplete and spare supraspinal pathways,especially those located within the peripheral white matter of the spinal cord,which includes reticulospinal pathways originating from the medullary reticular formation.Whereas there is abundant literature about the motor cortex,its corticospinal pathway,and its capacity to modulate functional recovery after SCI,less is known about the medullary reticular formation and its reticulospinal pathway.
基金Funding from Natural Sciences and Engineering Research Council of Canada award number RGPIN/4002-2020.
文摘Viral diseases are an important threat to crop yield,as they are responsible for losses greater than US$30 billion annually.Thus,understanding the dynamics of virus propagation within plant cells is essential for devising effective control strategies.However,viruses are complex to propagate and quantify.Existing methodologies for viral quantification tend to be expensive and time-consuming.Here,we present a rapid cost-effective approach to quantify viral propagation using an engineered virus expressing a fluorescent reporter.Using a microplate reader,we measured viral protein levels and we validated our findings through comparison by western blot analysis of viral coat protein,the most common approach to quantify viral titer.Our proposed methodology provides a practical and accessible approach to studying virus-host interactions and could contribute to enhancing our understanding of plant virology.
基金funded by Environment and Climate Change Canada(Fonds pour dommages a l’environnement)under a grant given to L.Vandelac and L.Parentthe Fondation UQAM(2020 to 2022)+2 种基金the Collectif de recherche Ecosante sur les pesticides,les politiques et les alternatives(CREPPA)the Natural Sciences and Engineering Research Council of Canada(NSERC)under a grant given to M.Boily(No.RGPIN-2016–05142)the Centre de recherche en ecotoxicologie du Quebec(EcotoQ) and the Centre interdisciplinaire de recherche en operationnalisation du developpement durable(CIRODD)for scholarships attributed to Y.Nombre.
文摘The active ingredient(a.i.)glyphosate is frequently detected in waterways at relatively high concentrations,posing a risk to aquatic organisms including freshwater mussels,North America’s most endangered animal group.This research aims to evaluate for the first time the effect of a glyphosate-based herbicide on a freshwater mussel(Unionid)using a battery of biomarkers.Themussel Elliptio complanata was exposed for 21 days to CreditR Xtreme(at 0,50,100,and 150μg/L a.i.of glyphosate).An integrated biomarker response(IBRv2)was used to visualize the overall impact of each glyphosate-based herbicide concentration on mussels’health conditions.The biomarker results showed that glyphosate(used at 100μg/L and 150μg/L)induced lipid peroxidation in the gills and digestive gland and inhibited acetylcholinesterase in the foot and gills,indicating oxidative damage and neurotoxicity.Other biomarkerswere influenced at the lowest concentration of glyphosate tested(50μg/L):lipids(decrease),triglycerides(increase)and,to a lesser extent,vitellogenin(decrease).For the latter biomarkers,the sexeswere not affected similarly,and theywere only sensitive at 50μg/L,only females showed a trend toward a decrease for vitellogenin and a decrease for lipids.Using IBRv2,we found a clear discrimination between concentrations,and the index values increased with glyphosate concentration,attesting to the deterioration in biomarker-defined mussel health when exposed to Credit® Xtreme at realistic glyphosate concentrations in agricultural rivers.This study shows that glyphosate-based herbicides can alter neurological function,induce oxidative damage,and selectively modify the E.complanata metabolism at relatively low concentrations.
基金the financial contribution of the Groupe de Recherche En Médecine d’Urgence du CHUL (GREMUC)which is the local emergency department research group。
文摘Febrile infants are at greater risk of invasive bacterial infections (IBI),which include bacterial meningitis and bacteremia.Although bacterial meningitis is uncommon,^([1-2])it remains a concern for clinicians treating infants younger than 90 d.Guidelines for investigating fever without a source(meaning without an apparent source of infection,or of nonobvious origin) are numerous around the world but remain conflicting,particularly on whether to perform a lumbar puncture for cerebrospinal fluid (CSF) analysis in infants older than 22 d and hence at lower risk than younger infants.
基金funded by the Natural Sciences and Engineering Research Council of Canada(NSERC)for financial support,Grant Nos.CG125664 and GF136078.
文摘In this study,two series of foams based on tannic acid(TA),furfuryl alcohol(FA),soybean protein isolate(SPI),and casein(CA),namely TA–FA–SPI(TS series)and TA–FA–CA(TC series)were developed,and their properties were enhanced by adding poplar fibers(WF).From the samples produced,a complete set of characterization was performed including possible crosslinking reactions,morphology,mechanical properties,flame retardancy,thermal insulation and thermal stability.Fourier-transform infrared spectroscopy(FTIR)revealed possible covalent crosslinking among the components and hydrogen bonding between WF and the matrix.Viscosity results indicated that lower prepolymer viscosity led to lower apparent density,while WF addition reduced even more the density.Mechanical tests showed that the maximum compressive strengths were good,while WF improved the compressive strength by up to 56%.Scanning electron microscopy(SEM)showed uniform cell structures,but small open pores were observed.Two-dimensional(2D)CT scan images confirmed the good compatibility between WF and the matrix,with low anisotropy in the material.Friability tests indicated that WF decreased the pulverization ratio of the materials by up to 42%.Thermogravimetric analysis(TGA)showed good thermal stability of the materials up to 328°C.Vertical burning tests showed that the materials were self-extinguishing without residue(dripping).The lowest thermal conductivity was 0.04 W/m·K.These results suggest that these novel formaldehyde-free,high biomass content(95%–96%)foams and composite foams have high potential to replace traditional phenolic foams(PF)in applications such as construction,transportation,packaging,and thermal insulation.
基金supported by the National Natural Science Foundation of China(22005072,21965006)Guizhou Provincial Key Technology R&D Program(Qian Ke He support(2023)General 122)+3 种基金Guiyang Guian Science and Technology Personnel Training Project([2024]2-13)Youth Science and Technology Talent Development Project from Guizhou Provincial Department of Education(KY[2022]163)Guizhou Provincial Science and Technology Foundation(KYJZ[2024]029)the ETS Marcelle-Gauvreau Engineering Research Chair program.
文摘Atomically dispersed metal site(ADMS)materials have emerged as a promising class of materials for electrocatalysis reactions in the field of energy conversion.Characterized by individual metal atoms dispersed on suitable supports,ADMS materials provide unique catalytic sites with highly tunable electronic structures.This review summarizes recent advancements in the field,with a focus on the critical roles of support materials,coordination environments,and the mechanisms underlying catalytic activity at the atomic level.First,commonly used density functional theory(DFT)simulations are reviewed,emphasizing their pivotal role in elucidating reaction mechanisms and predicting the behavior of ADMS in electrochemical reactions for hydrogen energy utilization.Then,advancements in ADMS for half-cell electrochemical reactions,including oxygen evolution reaction,hydrogen evolution reaction,and oxygen reduction reaction,as well as their applications in fuel cells and water splitting,are summarized.Finally,the challenges and future prospects of ADMS are discussed.This review underscores the transformative potential of ADMS in electrocatalysis,paving the way for innovative and sustainable energy conversion technologies.
基金funded by Vinnova,the Swedish Innovation Agency as a part of the Autoplant project(Dnr 2020-04202 and 2023-02747).
文摘Effective forest regeneration is essential for sustainable forestry practices.In Sweden,mechanical site preparation and manual planting is the dominating method,but sourcing labour for the physically demanding work is difficult.An autonomous scarifying and planting system(Autoplant)could meet the requirements of the forest industry and,for this,a tool for regeneration planning and routing is needed.The tool,Pathfinder,plans the regeneration and routes based on the harvested production(hpr)files,soil moisture and parent material maps,no-go areas(for culture or nature conservation),digital elevation models(DEM),and machine data(e.g.,working width,critical slope,time taken for different turn angles).The overall planting solution is either a set of capacity constrained routes or a continuous route and could be used for any planting machine as well as for traditional scarifiers as disc trenchers or mounders pulled by forwarders.Pathfinder was tested on eleven regeneration areas throughout Sweden,both with continuous routes and routes based on a carrying capacity of 1500 seedlings.The net operation area,species and seedling density suggestions were deemed relevant by expert judgement in the field.The routes provided by Pathfinder were compared with solutions given by two experienced drivers and a third solution based on the actual soil scarification at the site.Total driving distance did not differ significantly between the suggestions,but Pathfinder included less side-slope driving on steep slopes(≥27%or 15°)and medium slopes(15–27%).The chosen threshold value for steep slopes(where side-slope driving should be avoided)affects the routing,and a lower threshold means more turning and longer driving distance.Pathfinder is not only a tool for routing of planting machines,but also helps in planning of traditional regeneration by providing a more correct net area and tree species suggestions based on the growth of the previous stand.It also diminishes the risk of severe soil disturbance by excluding the wettest area in the planning.
