Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
10,831 Research products, page 1 of 1,084

  • Canada
  • ZENODO
  • International Journal of Environmental Research and Public Health

10
arrow_drop_down
Relevance
arrow_drop_down
  • Open Access English
    Authors: 
    Meixiu Yu; Daqing Yang; Xiaolong Liu; Qiongfang Li; Guoqing Wang;
    Publisher: MDPI AG
    Country: Netherlands

    Dam building and reservoir operations alter the downstream hydrological regime, and as a result, affect the health of the river aquatic ecosystem, particularly for large-scale cascade reservoirs. This study investigated the impact of the Gezhouba Reservoir (GR) and the Three Gorges Reservoir (TGR) on the spawning conditions of two critical taxa, i.e., the endemic four major carps and the endangered Chinese sturgeon in the Yangtze River. We analyzed the flow, sediment, and thermal regime in these two taxa spawning seasons and compared their features between the predam and postdam periods. Our results revealed that the GR and the TGR had altered the frequency distributions of flow, sediment, and water temperature to different degrees, with the impact by the GR on the carps and Chinese sturgeon ranked as water temperature > water temperature. For the GR, the satisfying degree of the suitable flow and water temperature of the carps increased, whilst the suitable flow, sediment, and water temperature for the Chinese sturgeon decreased. These changes in TGR showed a significant ascending (descending) trend in the suitable flow (water temperature) for the carps, and a clear decreasing trend in the flow, sediment, and temperature for Chinese sturgeon. Both the TGR and the GR had negative impacts on the spawning of these two taxa in terms of the rising/falling flow characteristics. flow, and the effect of the TGR on these two taxa were ordered as flow > water temperature, sediment > water temperature > flow, sediment > flow >

  • Publication . Article . 2020
    Open Access English
    Authors: 
    Tim Bayne; Anil K. Seth; Marcello Massimini;
    Countries: Italy, United Kingdom
    Project: EC | LUMINOUS (686764), EC | HBP SGA2 (785907), EC | HBP SGA3 (945539)

    Ordinary human experience is embedded in a web of causal relations that link the brain to the body and the wider environment. However, there might be conditions in which brain activity supports consciousness even when that activity is fully causally isolated from the body and its environment. Such cases would involve what we call islands of awareness: conscious states that are neither shaped by sensory input nor able to be expressed by motor output. This Opinion paper considers conditions in which such islands might occur, including ex cranio brains, hemispherotomy, and in cerebral organoids. We examine possible methods for detecting islands of awareness, and consider their implications for ethics and for the nature of consciousness.

  • Open Access English
    Authors: 
    Ben Vandermeer; Ingeborg van der Tweel; Marijke C. Jansen-van der Weide; Stephanie S. Weinreich; Despina G. Contopoulos-Ioannidis; Dirk Bassler; Ricardo M. Fernandes; Lisa M. Askie; Haroon Saloojee; Paola Baiardi; +2 more
    Countries: Switzerland, Netherlands
    Project: NWO | Blue Action (32188), EC | GRIP (261060)

    Background: We wished to compare the nuisance parameters of pediatric vs. adult randomized-trials (RCTs) and determine if the latter can be used in sample size computations of the former.Methods: In this meta-epidemiologic empirical evaluation we examined meta-analyses from the Cochrane Database of Systematic-Reviews, with at least one pediatric-RCT and at least one adult-RCT. Within each meta-analysis of binary efficacy-outcomes, we calculated the pooled-control-group event-rate (CER) across separately all pediatric and adult-trials, using random-effect models and subsequently calculated the control-group event-rate risk-ratio (CER-RR) of the pooled-pediatric-CERs vs. adult-CERs. Within each meta-analysis with continuous outcomes we calculated the pooled-control-group effect standard deviation (CE-SD) across separately all pediatric and adult-trials and subsequently calculated the CE-SD-ratio of the pooled-pediatric-CE-SDs vs. adult-CE-SDs. We then calculated across all meta-analyses the pooled-CER-RRs and pooled-CE-SD-ratios (primary endpoints) and the pooled-magnitude of effect-sizes of CER-RRs and CE-SD-ratios using REMs. A ratio < 1 indicates that pediatric trials have smaller nuisance parameters than adult trials.Results: We analyzed 208 meta-analyses (135 for binary-outcomes, 73 for continuous-outcomes). For binary outcomes, pediatric-RCTs had on average 10% smaller CERs than adult-RCTs (summary-CE-RR: 0.90; 95% CI: 0.83, 0.98). For mortality outcomes the summary-CE-RR was 0.48 (95% CIs: 0.31, 0.74). For continuous outcomes, pediatric-RCTs had on average 26% smaller CE-SDs than adult-RCTs (summary-CE-SD-ratio: 0.74).Conclusions: Clinically relevant differences in nuisance parameters between pediatric and adult trials were detected. These differences have implications for design of future studies. Extrapolation of nuisance parameters for sample-sizes calculations from adult-trials to pediatric-trials should be cautiously done.

  • Open Access
    Authors: 
    Mansour Bechar; Abdeldjebar Hazzab; Mohamed Habbab; Pierre Sicard;
    Publisher: Institute of Advanced Engineering and Science

    In this paper, Reduced-Order Observer For Real-Time Implementation Speed Sensorless Control of Induction Using RT-LAB Softwareis presented. Speed estimation is performed through a reduced-order observer. The stability of the proposed observer is proved based on Lyapunov’s theorem. The model is initially built offline using Matlab/Simulink and implemented in real-time environment using RT-LAB package and an OP5600 digital simulator. RT-LAB configuration has two main subsystems master and console subsystems. These two subsystems were coordinated to achieve the real-time simulation. In order to verify the feasibility and effectiveness of proposed method, experimental results are presented over a wide speed range, including zero speed.

  • Closed Access
    Authors: 
    Stephen A. Marshall;
    Publisher: Magnolia Press

    The Micropezidae of Madagascar are reviewed, and the endemic genus Paramimegralla Hennig is revised. Twenty species are recognized including two Hybobata species and 18 Paramimegralla species, of which 12 are described as new (P. luteoscapus , brunnea , zinzala, zarpa, verticalis, taeniola, sulcata, campanula, anchivitta, quadrifasciata and longicephala ). Stiltissima Barraclough is synonymized with Paramimegralla Hennig and previous records of Rainieria Rondani from the island are shown to be incorrect. Paramimegralla steineri (Barraclough) and Paramimegralla volcanica (Barraclough) are given as new combinations, Paramimegralla stuckenbergi Barraclough is synonymized with P. nigra Barraclough, and Hybobata Enderlein is resurrected from synonymy with Mimegralla Rondani. All known Malagasy micropezid species are keyed and illustrated and all Paramimegralla species are described or redescribed.

  • Publication . Article . Other literature type . 2021
    Open Access English
    Authors: 
    Usha George; Mary Susan Thomson; Ferzana Chaze; Sepali Guruge;
    Publisher: MDPI AG

    The Mental Health Commission of Canada’s (MHCC) strategy calls for promoting the health and wellbeing of all Canadians and to improve mental health outcomes. Each year, one in every five Canadians experiences one or more mental health problems, creating a significant cost to the health system. Mental health is pivotal to holistic health and wellbeing. This paper presents the key findings of a comprehensive literature review of Canadian research on the relationship between settlement experiences and the mental health and well-being of immigrants and refugees. A scoping review was conducted following a framework provided by Arskey and O’Malley (Int J Soc Res Methodol 8:19–32, 2005). Over two decades of relevant literature on immigrants’ health in Canada was searched. These included English language peer-reviewed publications from relevant online databases Medline, Embase, PsycInfo, Healthstar, ERIC and CINAHL between 1990 and 2015. The findings revealed three important ways in which settlement affects the mental health of immigrants and refugees: through acculturation related stressors, economic uncertainty and ethnic discrimination. The recommendations for public health practice and policy are discussed.

  • Open Access
    Authors: 
    M.M. Freda; Jianfeng Weng; Tho Le-Ngoc;
    Publisher: IEEE

    In this paper, we present a joint channel estimation and synchronization technique for burst-mode OFDM systems. The technique uses the nonlinear recursive least squares algorithm (NL-RLS) to jointly estimate the channel impulse response (CIR), the carrier frequency offset (CFO), the sampling clock offset (SCO), and the timing offset, and to correct for each of these in the digital domain and without the use of a delay-locked loop (DLL). The need for pilot symbols in the payload data is eliminated by a decision-directed operation mode. The time-domain NL-RLS algorithm needs a small number of parameters to be estimated and can suppress the effect of decision feedback errors. Simulation results confirm its improved performance and relatively low variance.

  • Open Access
    Authors: 
    Adam Brunke; Alexey Solodovnikov;
    Publisher: Pensoft Publishers
    Project: NSERC

    The Neotropical species of the rarely collected genus Bolitogyrus (Coleoptera: Staphylinidae: Staphylininae: Staphylinini) are revised. The genus exhibits an uncommon, disjunct distribution between the Neotropical and Oriental Regions and is of unknown phylogenetic position within Staphylinini. Morphological evolution remarkable for Staphylinini was discovered within Bolitogyrus, including sexually dimorphic modifications of the pronotum that may be involved in male competition for females. rSEM interactive animations were used to establish morphological species boundaries between two highly variable species and are provided to illustrate diagnostic characters of the genitalia in unconventional views. The genus is redescribed based on the world fauna and twenty-eight Neotropical species are considered valid. Of these, nineteen are described as new to science: Bolitogyrus ashei sp. n.; B. apicofasciatus sp. n.; B. brevistellus sp. n.; B. bufo sp. n.; B. cheungi sp. n.; B. cornutus sp. n.; B. divisus sp. n.; B. falini sp. n.; B. gracilis sp. n.; B. inexspectatus sp. n.; B. longistellus sp. n.; B. marquezi sp. n.; B. newtoni sp. n.; B. pseudotortifolius sp. n.; B. pulchrus sp. n.; B. silex sp. n.; B. thomasi sp. n.; B. tortifolius sp. n.; and B. viridescens sp. n. Bolitogyrus sallei (Kraatz), stat. r. is removed from synonymy with B. buphthalmus (Erichson) and the following new synonyms are proposed: Cyrtothorax cyanescens Sharp, 1884, syn. n. = Quedius buphthalmus Erichson, 1840; C. nevermanni Scheerpeltz, 1974, syn. n. = C. costaricensis Wendeler, 1927. A summary of all available bionomic and distributional data, as well as an illustrated identification key to and diagnoses of all Neotropical species are provided.

  • Open Access
    Authors: 
    Tobias Karlberg; R. Collins; Susanne van den Berg; A. Flores; Martin Hammarström; Martin Högbom; Lovisa Holmberg Schiavone; J. Uppenberg;
    Publisher: Zenodo

    Argininosuccinate synthetase catalyzes the transformation of citrulline and aspartate into argininosuccinate and pyrophos­phate using the hydrolysis of ATP to AMP and pyrophos­phate. This enzymatic process constitutes the rate-limiting step in both the urea and arginine–citrulline cycles. Previous studies have investigated the crystal structures of argininosuccinate synthetase from bacterial species. In this work, the first crystal structure of human argininosuccinate synthetase in complex with the substrates citrulline and aspartate is presented. The human enzyme is compared with structures of argininosuccinate synthetase from bacteria. In addition, the structure also provides new insights into the function of the numerous clinical mutations identified in patients with type I citrullinaemia (also known as classic citrullinaemia).

  • Open Access English
    Authors: 
    William O'Grady; Patrick Parnaby; Justin Schikschneit;
    Publisher: Zenodo

    Al'aide de donnees recueillies lors de la couverture d'evenements par la presse locale, on examine comment a etepresentele meurtre d'un jeune de 15 ans, Jordan Manners, commis dans une ecole secondaire de Toronto. En particulier, on cherche acomprendre pourquoi, apres avoir d'abord tentede contextualiser l'evenement en fonction d'autres cas de tireurs dans des ecoles, les medias ont ensuite adopteun cadre d'interpretation basesur des presup- positions ideologiques liees aux classes marginales de Toronto. Quand les medias veulent absolument couvrir un evenement malgrel'absence de renseignements essentiels, on note qu'ils on tendance areprendre des cadres conformistes. Dans la conclusion, on etudie la signification sociopolitique de ces cadres essentialises pour les crimes commis dans les collectivites pauvres, habitees principalement par des personnes de couleur. Mots cles : constructionnisme, media, crime, tireur dans les ecoles, classes marginales Using data gathered from local press coverage, this article examines how the shooting death of 15-year-old Jordan Manners at a Toronto high school was framed. In particular, we seek to explain why the media's initial attempt to contextualize the event vis-a`-vis the tragedy of past school shootings eventually gave way to an interpretive frame rooted in ideological presuppositions about Toronto's underclass. We argue that when the media are confronted with a ''must cover'' event but lack essential informa- tion, the tendency is to adopt pre-existing, consonant frameworks. We con- clude by exploring the socio-political significance of such essentializing frames vis-a`-vis crime in poor communities inhabited mainly by people of colour.

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
10,831 Research products, page 1 of 1,084
  • Open Access English
    Authors: 
    Meixiu Yu; Daqing Yang; Xiaolong Liu; Qiongfang Li; Guoqing Wang;
    Publisher: MDPI AG
    Country: Netherlands

    Dam building and reservoir operations alter the downstream hydrological regime, and as a result, affect the health of the river aquatic ecosystem, particularly for large-scale cascade reservoirs. This study investigated the impact of the Gezhouba Reservoir (GR) and the Three Gorges Reservoir (TGR) on the spawning conditions of two critical taxa, i.e., the endemic four major carps and the endangered Chinese sturgeon in the Yangtze River. We analyzed the flow, sediment, and thermal regime in these two taxa spawning seasons and compared their features between the predam and postdam periods. Our results revealed that the GR and the TGR had altered the frequency distributions of flow, sediment, and water temperature to different degrees, with the impact by the GR on the carps and Chinese sturgeon ranked as water temperature > water temperature. For the GR, the satisfying degree of the suitable flow and water temperature of the carps increased, whilst the suitable flow, sediment, and water temperature for the Chinese sturgeon decreased. These changes in TGR showed a significant ascending (descending) trend in the suitable flow (water temperature) for the carps, and a clear decreasing trend in the flow, sediment, and temperature for Chinese sturgeon. Both the TGR and the GR had negative impacts on the spawning of these two taxa in terms of the rising/falling flow characteristics. flow, and the effect of the TGR on these two taxa were ordered as flow > water temperature, sediment > water temperature > flow, sediment > flow >

  • Publication . Article . 2020
    Open Access English
    Authors: 
    Tim Bayne; Anil K. Seth; Marcello Massimini;
    Countries: Italy, United Kingdom
    Project: EC | LUMINOUS (686764), EC | HBP SGA2 (785907), EC | HBP SGA3 (945539)

    Ordinary human experience is embedded in a web of causal relations that link the brain to the body and the wider environment. However, there might be conditions in which brain activity supports consciousness even when that activity is fully causally isolated from the body and its environment. Such cases would involve what we call islands of awareness: conscious states that are neither shaped by sensory input nor able to be expressed by motor output. This Opinion paper considers conditions in which such islands might occur, including ex cranio brains, hemispherotomy, and in cerebral organoids. We examine possible methods for detecting islands of awareness, and consider their implications for ethics and for the nature of consciousness.

  • Open Access English
    Authors: 
    Ben Vandermeer; Ingeborg van der Tweel; Marijke C. Jansen-van der Weide; Stephanie S. Weinreich; Despina G. Contopoulos-Ioannidis; Dirk Bassler; Ricardo M. Fernandes; Lisa M. Askie; Haroon Saloojee; Paola Baiardi; +2 more
    Countries: Switzerland, Netherlands
    Project: NWO | Blue Action (32188), EC | GRIP (261060)

    Background: We wished to compare the nuisance parameters of pediatric vs. adult randomized-trials (RCTs) and determine if the latter can be used in sample size computations of the former.Methods: In this meta-epidemiologic empirical evaluation we examined meta-analyses from the Cochrane Database of Systematic-Reviews, with at least one pediatric-RCT and at least one adult-RCT. Within each meta-analysis of binary efficacy-outcomes, we calculated the pooled-control-group event-rate (CER) across separately all pediatric and adult-trials, using random-effect models and subsequently calculated the control-group event-rate risk-ratio (CER-RR) of the pooled-pediatric-CERs vs. adult-CERs. Within each meta-analysis with continuous outcomes we calculated the pooled-control-group effect standard deviation (CE-SD) across separately all pediatric and adult-trials and subsequently calculated the CE-SD-ratio of the pooled-pediatric-CE-SDs vs. adult-CE-SDs. We then calculated across all meta-analyses the pooled-CER-RRs and pooled-CE-SD-ratios (primary endpoints) and the pooled-magnitude of effect-sizes of CER-RRs and CE-SD-ratios using REMs. A ratio < 1 indicates that pediatric trials have smaller nuisance parameters than adult trials.Results: We analyzed 208 meta-analyses (135 for binary-outcomes, 73 for continuous-outcomes). For binary outcomes, pediatric-RCTs had on average 10% smaller CERs than adult-RCTs (summary-CE-RR: 0.90; 95% CI: 0.83, 0.98). For mortality outcomes the summary-CE-RR was 0.48 (95% CIs: 0.31, 0.74). For continuous outcomes, pediatric-RCTs had on average 26% smaller CE-SDs than adult-RCTs (summary-CE-SD-ratio: 0.74).Conclusions: Clinically relevant differences in nuisance parameters between pediatric and adult trials were detected. These differences have implications for design of future studies. Extrapolation of nuisance parameters for sample-sizes calculations from adult-trials to pediatric-trials should be cautiously done.

  • Open Access
    Authors: 
    Mansour Bechar; Abdeldjebar Hazzab; Mohamed Habbab; Pierre Sicard;
    Publisher: Institute of Advanced Engineering and Science

    In this paper, Reduced-Order Observer For Real-Time Implementation Speed Sensorless Control of Induction Using RT-LAB Softwareis presented. Speed estimation is performed through a reduced-order observer. The stability of the proposed observer is proved based on Lyapunov’s theorem. The model is initially built offline using Matlab/Simulink and implemented in real-time environment using RT-LAB package and an OP5600 digital simulator. RT-LAB configuration has two main subsystems master and console subsystems. These two subsystems were coordinated to achieve the real-time simulation. In order to verify the feasibility and effectiveness of proposed method, experimental results are presented over a wide speed range, including zero speed.

  • Closed Access
    Authors: 
    Stephen A. Marshall;
    Publisher: Magnolia Press

    The Micropezidae of Madagascar are reviewed, and the endemic genus Paramimegralla Hennig is revised. Twenty species are recognized including two Hybobata species and 18 Paramimegralla species, of which 12 are described as new (P. luteoscapus , brunnea , zinzala, zarpa, verticalis, taeniola, sulcata, campanula, anchivitta, quadrifasciata and longicephala ). Stiltissima Barraclough is synonymized with Paramimegralla Hennig and previous records of Rainieria Rondani from the island are shown to be incorrect. Paramimegralla steineri (Barraclough) and Paramimegralla volcanica (Barraclough) are given as new combinations, Paramimegralla stuckenbergi Barraclough is synonymized with P. nigra Barraclough, and Hybobata Enderlein is resurrected from synonymy with Mimegralla Rondani. All known Malagasy micropezid species are keyed and illustrated and all Paramimegralla species are described or redescribed.

  • Publication . Article . Other literature type . 2021
    Open Access English
    Authors: 
    Usha George; Mary Susan Thomson; Ferzana Chaze; Sepali Guruge;
    Publisher: MDPI AG

    The Mental Health Commission of Canada’s (MHCC) strategy calls for promoting the health and wellbeing of all Canadians and to improve mental health outcomes. Each year, one in every five Canadians experiences one or more mental health problems, creating a significant cost to the health system. Mental health is pivotal to holistic health and wellbeing. This paper presents the key findings of a comprehensive literature review of Canadian research on the relationship between settlement experiences and the mental health and well-being of immigrants and refugees. A scoping review was conducted following a framework provided by Arskey and O’Malley (Int J Soc Res Methodol 8:19–32, 2005). Over two decades of relevant literature on immigrants’ health in Canada was searched. These included English language peer-reviewed publications from relevant online databases Medline, Embase, PsycInfo, Healthstar, ERIC and CINAHL between 1990 and 2015. The findings revealed three important ways in which settlement affects the mental health of immigrants and refugees: through acculturation related stressors, economic uncertainty and ethnic discrimination. The recommendations for public health practice and policy are discussed.

  • Open Access
    Authors: 
    M.M. Freda; Jianfeng Weng; Tho Le-Ngoc;
    Publisher: IEEE

    In this paper, we present a joint channel estimation and synchronization technique for burst-mode OFDM systems. The technique uses the nonlinear recursive least squares algorithm (NL-RLS) to jointly estimate the channel impulse response (CIR), the carrier frequency offset (CFO), the sampling clock offset (SCO), and the timing offset, and to correct for each of these in the digital domain and without the use of a delay-locked loop (DLL). The need for pilot symbols in the payload data is eliminated by a decision-directed operation mode. The time-domain NL-RLS algorithm needs a small number of parameters to be estimated and can suppress the effect of decision feedback errors. Simulation results confirm its improved performance and relatively low variance.

  • Open Access
    Authors: 
    Adam Brunke; Alexey Solodovnikov;
    Publisher: Pensoft Publishers
    Project: NSERC

    The Neotropical species of the rarely collected genus Bolitogyrus (Coleoptera: Staphylinidae: Staphylininae: Staphylinini) are revised. The genus exhibits an uncommon, disjunct distribution between the Neotropical and Oriental Regions and is of unknown phylogenetic position within Staphylinini. Morphological evolution remarkable for Staphylinini was discovered within Bolitogyrus, including sexually dimorphic modifications of the pronotum that may be involved in male competition for females. rSEM interactive animations were used to establish morphological species boundaries between two highly variable species and are provided to illustrate diagnostic characters of the genitalia in unconventional views. The genus is redescribed based on the world fauna and twenty-eight Neotropical species are considered valid. Of these, nineteen are described as new to science: Bolitogyrus ashei sp. n.; B. apicofasciatus sp. n.; B. brevistellus sp. n.; B. bufo sp. n.; B. cheungi sp. n.; B. cornutus sp. n.; B. divisus sp. n.; B. falini sp. n.; B. gracilis sp. n.; B. inexspectatus sp. n.; B. longistellus sp. n.; B. marquezi sp. n.; B. newtoni sp. n.; B. pseudotortifolius sp. n.; B. pulchrus sp. n.; B. silex sp. n.; B. thomasi sp. n.; B. tortifolius sp. n.; and B. viridescens sp. n. Bolitogyrus sallei (Kraatz), stat. r. is removed from synonymy with B. buphthalmus (Erichson) and the following new synonyms are proposed: Cyrtothorax cyanescens Sharp, 1884, syn. n. = Quedius buphthalmus Erichson, 1840; C. nevermanni Scheerpeltz, 1974, syn. n. = C. costaricensis Wendeler, 1927. A summary of all available bionomic and distributional data, as well as an illustrated identification key to and diagnoses of all Neotropical species are provided.

  • Open Access
    Authors: 
    Tobias Karlberg; R. Collins; Susanne van den Berg; A. Flores; Martin Hammarström; Martin Högbom; Lovisa Holmberg Schiavone; J. Uppenberg;
    Publisher: Zenodo

    Argininosuccinate synthetase catalyzes the transformation of citrulline and aspartate into argininosuccinate and pyrophos­phate using the hydrolysis of ATP to AMP and pyrophos­phate. This enzymatic process constitutes the rate-limiting step in both the urea and arginine–citrulline cycles. Previous studies have investigated the crystal structures of argininosuccinate synthetase from bacterial species. In this work, the first crystal structure of human argininosuccinate synthetase in complex with the substrates citrulline and aspartate is presented. The human enzyme is compared with structures of argininosuccinate synthetase from bacteria. In addition, the structure also provides new insights into the function of the numerous clinical mutations identified in patients with type I citrullinaemia (also known as classic citrullinaemia).

  • Open Access English
    Authors: 
    William O'Grady; Patrick Parnaby; Justin Schikschneit;
    Publisher: Zenodo

    Al'aide de donnees recueillies lors de la couverture d'evenements par la presse locale, on examine comment a etepresentele meurtre d'un jeune de 15 ans, Jordan Manners, commis dans une ecole secondaire de Toronto. En particulier, on cherche acomprendre pourquoi, apres avoir d'abord tentede contextualiser l'evenement en fonction d'autres cas de tireurs dans des ecoles, les medias ont ensuite adopteun cadre d'interpretation basesur des presup- positions ideologiques liees aux classes marginales de Toronto. Quand les medias veulent absolument couvrir un evenement malgrel'absence de renseignements essentiels, on note qu'ils on tendance areprendre des cadres conformistes. Dans la conclusion, on etudie la signification sociopolitique de ces cadres essentialises pour les crimes commis dans les collectivites pauvres, habitees principalement par des personnes de couleur. Mots cles : constructionnisme, media, crime, tireur dans les ecoles, classes marginales Using data gathered from local press coverage, this article examines how the shooting death of 15-year-old Jordan Manners at a Toronto high school was framed. In particular, we seek to explain why the media's initial attempt to contextualize the event vis-a`-vis the tragedy of past school shootings eventually gave way to an interpretive frame rooted in ideological presuppositions about Toronto's underclass. We argue that when the media are confronted with a ''must cover'' event but lack essential informa- tion, the tendency is to adopt pre-existing, consonant frameworks. We con- clude by exploring the socio-political significance of such essentializing frames vis-a`-vis crime in poor communities inhabited mainly by people of colour.