75 research outputs found

    Emerging Territories of Digital Material Practice

    Get PDF
    <p>This paper explores the emerging future field of fabric form work for concrete structures in combination with 3D printing. The showcased material experimentations represent studies which focus on the simultaneous use of fabric formwork and textile 3D printing in order to create a new type of material process for forming and fabricating non standard geometries applied to architectural elements. Textiles in combination with 3D printed patterning are seen in this context as tools for form generation and to a certain extent also for form control.  </p><p>This practice-based research offers a new alternative to predominant fabrication methods for complex geometries, showcasing the benefits of hybrid digital crafting techniques. The developed manufacturing strategy will be explained through a series of material experimentations and resulting prototypes. The following studies investigate fabrication processes and surface texturing methods for the manufacturing of small and large-scale prototypes such as tiles or concrete columns. The studies represent material investigations with a hybrid material system —textile, concrete and 3D printed silicone— and are process driven, concentrating more on process experimentation —seen as a digital crafting methodology — rather than focussing on a predefined design output.<br></p

    “We Used to Say Rats Fell from the Sky After a Flood:” Temporary Recovery of Muskrat Following Ice Jams in the Peace-Athabasca Delta

    Get PDF
    Elders and Indigenous land users in the Peace-Athabasca Delta (PAD) have observed a dramatic decline in the relative abundance of muskrat in recent decades (~1935–2014). The main explanation for the decline has been reduction in suitable habitat as a result of decades with reduced frequency of ice-jam flooding on the Peace River. Under favourable conditions, ice jams can cause flooding of perched basins within the PAD that would otherwise receive no recharge from floodwaters. To examine whether abundance of muskrat in the PAD is driven by flooding, we tested the predictions that the density of muskrat (estimated by winter counts of houses) (1) was inversely related to the number of years since major ice jam floods and (2) increased with water depth. An ongoing collaborative monitoring program initiated in 2011, combined with analysis of data from past surveys (1973–2015), allowed Indigenous land users and scientists to document a 10 to 100-fold increase in the density of muskrat houses in 24 basins, over the two years following ice-jam flood events in the PAD. During 1973–2015, in the periods between major floods, density of houses dropped by approximately 79% for every year after a significant flood. In 27 basins surveyed from 2011 to 2015, density of muskrat houses increased by two orders of magnitude in the two years following a flood in the spring of 2014. Density of muskrat houses had a non-linear relationship with estimated depth of water at the time of fall freeze-up; the highest densities of muskrat houses were in basins with about 60 – 250 cm of water at the time of freeze-up. The depth of snow at the time of surveys did not have a strong relationship with the density of muskrat houses. However, few houses were counted in basins with more than 20 cm of snow, likely because deeper snow made it more difficult to conduct surveys and spot houses. Factors other than an increase in the depth of water at fall freeze-up may provide the mechanisms by which flooding affects muskrat. Density of muskrat houses is clearly tied to ice-jam flooding in the PAD. However, the local mechanisms by which floods affect muskrat are best understood by Indigenous land users and remain poorly understood by Western science. Indigenous peoples continue to regard muskrat as an indicator of ecological and cultural health of the PAD. This study highlights the value of consistent ecological monitoring that includes Indigenous knowledge.Les aĂźnĂ©s et les utilisateurs des terres autochtones du delta des riviĂšres de la Paix et Athabasca ont observĂ© une baisse draconienne de l’abondance du rat musquĂ© au cours des derniĂšres dĂ©cennies (~1935-2014). La principale explication du dĂ©clin est la diminution d’abris convenables, et ce, en raison de plusieurs dĂ©cennies marquĂ©es par la frĂ©quence rĂ©duite d’inondations causĂ©es par des embĂącles dans la riviĂšre de la Paix. Dans des conditions favorables, les embĂącles peuvent causer l’inondation des bassins perchĂ©s au sein du delta des riviĂšres de la Paix et Athabasca qui autrement ne recevraient pas de recharge des eaux de crue. Afin d’examiner si l’abondance du rat musquĂ© dans le delta des riviĂšres de la Paix et Athabasca est favorisĂ©e par les inondations, nous avons testĂ© des prĂ©visions selon lesquelles la densitĂ© du rat musquĂ© (estimĂ©e par le nombre d’abris en hiver) 1) Ă©tait inversement liĂ©e au nombre d’annĂ©es depuis les derniĂšres importantes inondations causĂ©es par des embĂącles et 2) augmentait avec la profondeur de l’eau. Un programme collaboratif de suivi continu lancĂ© en 2011, combinĂ© Ă  l’analyse de donnĂ©es des relevĂ©s antĂ©rieurs (1973-2015), a permis aux utilisateurs des terres autochtones et aux scientifiques de multiplier de 10 Ă  100 fois la densitĂ© d’abris du rat musquĂ© dans 24 bassins, au cours des deux annĂ©es suivant des Ă©vĂ©nementsd’inondation causĂ©s par des embĂącles dans le delta des riviĂšres de la Paix et Athabasca. Entre 1973 et 2015, durant les pĂ©riodes se situant entre les inondations importantes, la densitĂ© d’abris a diminuĂ© d’environ 79 % chaque annĂ©e suivant une inondation importante. Dans 27 bassins sondĂ©s entre 2011 et 2015, la densitĂ© d’abris du rat musquĂ© a augmentĂ© de deux ordres de grandeur au cours des deux annĂ©es ayant suivi une inondation survenue au printemps de 2014. La densitĂ© d’abris du rat musquĂ© avait une relation non linĂ©aire avec la profondeur de l’eau estimĂ©e au moment de la prise des glaces en automne; les plus fortes densitĂ©s d’abris du rat musquĂ© se trouvaient dans les bassins ayant de 60 Ă  250 cm d’eau au moment de la prise des glaces. La profondeur de la neige au moment des relevĂ©s n’avait pas de relation solide avec la densitĂ© d’abris du rat musquĂ©. Cependant, nous avons comptĂ© peu d’abris dans les bassins comptant plus de 20 cm de neige, probablement parce qu’il Ă©tait plus difficile d’effectuer des relevĂ©s et de trouver les abris dans la neige plus Ă©paisse. Des facteurs autres que l’augmentation de la profondeur de l’eau au moment de la prise des glaces en automne pourraient fournir les mĂ©canismes par lesquels les inondations se rĂ©percutent sur les rats musquĂ©s. La densitĂ© d’abris du rat musquĂ© est manifestement liĂ©e aux inondations causĂ©es par des embĂącles dans le delta des riviĂšres de la Paix et Athabasca. Toutefois, les utilisateurs des terres autochtones comprennent mieux les mĂ©canismes locaux par lesquels les inondations se rĂ©percutent sur les rats musquĂ©s, tandis qu’ils demeurent mal compris par la science occidentale. Les peuples autochtones continuent de considĂ©rer le rat musquĂ© comme un indicateur de la santĂ© Ă©cologique et culturelle du delta des riviĂšres de la Paix et Athabasca. Cette Ă©tude fait ressortir la valeur d’un suivi Ă©cologique constant qui tient compte des connaissances autochtones

    Configural and featural information in facial-composite images

    Get PDF
    Eyewitnesses are often invited to construct a facial composite, an image created of the person they saw commit a crime that is used by law enforcement to locate criminal suspects. In the current paper, the effectiveness of composite images was investigated from traditional feature systems (E-FIT and PRO-fit), where participants (face constructors) selected individual features to build the face, and a more recent holistic system (EvoFIT), where they &lsquo;evolved' a composite by repeatedly selecting from arrays of complete faces. Further participants attempted to name these composites when seen as an unaltered image, or when blurred, rotated, linearly stretched or converted to a photographic negative. All of the manipulations tested reduced correct naming of the composites overall except (i) for a low level of blur, for which naming improved for holistic composites but reduced for feature composites, and (ii) for 100% linear stretch, for which a substantial naming advantage was observed. Results also indicated that both featural (facial elements) and configural (feature spacing) information was useful for recognition in both types of composite system, but highly-detailed information was more accurate in the feature-based than the holistic method. The naming advantage of linear stretch was replicated using a forensically more-practical procedure with observers viewing an unaltered &not;composite sideways. The work is valuable to police practitioners and designers of facial-composite systems

    Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries

    Get PDF
    Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management

    Diving into the vertical dimension of elasmobranch movement ecology

    Get PDF
    Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

    Diving into the vertical dimension of elasmobranch movement ecology

    Get PDF
    Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

    Diving into the vertical dimension of elasmobranch movement ecology

    Get PDF
    Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

    Get PDF
    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
    • 

    corecore