880 research outputs found
Geology of Canadian Wetlands
Wetlands have not gained as much attention as they ought to by geologists despite being so prevalent in the Canadian landscape. Some of this stems from a poor understanding of wetland geology and what wetland landforms are. Wetlands constitute unusual landformsin that they are formed of biological material predominantly shaped by biological processes rather than being formed of minerals and rock shaped more by physical processes. There are two main groups of wetlands: mineral wetlands, commonly situated in high-energy settings; and peatlands, situated in low-energy settings that undergo either terrestrialization or paludification during the course of their development.
Wetlands, as both a landscape unit and economic resource, have historically been and will continue to be important in Canada. New and more specialized skills and engineering designs will be required to build infrastructurein wetland terrain. Wetlands should be regarded as an economic resource that requires wise use and management. Nature-sensitive technologies need to be invented for use with wetlands to conserve and enhance the resource to serve the needs and protect the health of human society.
RĂSUMĂ
Bien qu'elles constituent un trait dominant du paysage canadien, les gĂ©ologues n'ont pas prĂȘtĂ© suffisamment d'attention aux terres humides. Cela tient en partie Ă une mauvaise connaissance de la gĂ©ologie des terres humides et de ce que sont ces Ă©lĂ©ments gĂ©omorphologiques. Comme Ă©lĂ©ments gĂ©omorphologiques, les terres humides ont ceci de particulier qu'elles sont principalement constituĂ©es de matĂ©riaux biologiques issus de processus biologiques, et non de minĂ©raux et de roches formĂ©es par des processus physiques. Il existe deux grands groupes de terres humides, soit les terres humides minĂ©rales, gĂ©nĂ©ralement situĂ©es en milieux de hautes Ă©nergies, et les tourbiĂšres, situĂ©es en milieux de basses Ă©nergies, et dont le dĂ©veloppement comporte une Ă©tape de terrestrialisation ou de tourbification.
Tant comme Ă©lĂ©ment topographique que ressource Ă©conomique, les terres humides ont Ă©tĂ© et demeurent importantes au Canada. Des savoirfaire techniques nouveaux et plus spĂ©cialisĂ©s seront nĂ©cessaires pour concevoir et Ă©difier des infrastructures en milieux humides. On devrait voir les terres humides comme une ressource Ă©conomique devant ĂȘtre gĂ©rer avec sagesse. Il est nĂ©cessaire que des technologies douces soient inventĂ©es pour conserver la ressource et en tirer un meilleur parti tout en protĂ©geant la santĂ© humaine
Testate amoebae analysis in ecological and paleoecological studies of wetlands: past, present and future
Testate amoebae are an abundant and diverse polyphyletic group of shelled protozoa living in aquatic to moist habitats ranging from estuaries to lakes, rivers, wetlands, soils, litter, and moss habitats. Owing to the preservation of shells in sediments, testate amoebae are useful proxy indicators complementary to long-established indicators such as pollen and spores or macrofossils. Their primary use to date has been for inferring past moisture conditions and climate in ombrotrophic peatlands and, to a lesser extent, to infer pH in peatlands and the trophic or nutrient status of lakes. Recent research on these organisms suggests other possible uses in paleoecology and ecology such as sea-level reconstruction in estuarine environments, as indicators of soil or air pollution, and monitoring recovery of peatland. We review the past and present use of testate amoebae, the challenges in current research, and provide some ideas on future research direction
A Sequential Bayesean Approach to History Taking and Diagnosis
journal articleBiomedical Informatic
A rare case of massive lower gastrointestinal bleeding from a ruptured splenic artery aneurysm
Pollen, Plant Macrofossils, and Insects from Fossil Woodrat (Neotoma Cinerea) Middens in British Columbia
Bushy-tailed woodrats (Neotoma cinerea) occur commonly in cliffs, rock talus, and caves in the open Pseudotsuga menziesii and Pinus ponderosa forests throughout interior British Columbia. Fossil N. cinerea middens from two sites in central British Columbia were radiocarbon dated and examined for pollen, plant macrofossils and insect remains. The Oregon Jack Creek site contains a midden that is dated 1150 ± 80 (WAT-1764) radiocarbon years ago. Pollen analyses reveal an abundance of Cupressaceae (Juniperus) and Pinus. Shrub and herb pollen types include Artemisia. Fabaceae, Poaceae, and Asteraceae. Juniperus scopulorum leaves, Pseudotsuga menziesii needles, Chenopodiaceae seeds. Rosa thorns and Artemisia leaflets are the main plant macrofossils. The remains of three beetle genera, Cryptophagus, Lathridius, and Enicmus represent insects that probably lived in the midden, eating decaying organic matter or moulds. Click beetle (Limonius) remains were probably brought into the midden from nearby soil or plant material. The Bull Canyon site contains a midden that dates to 700 ± 80 (WAT-1765) years BP. Pollen and plant macrofossil assemblages are similar to those at the Oregon Jack Creek site. Woodrat middens offer a new dimension in reconstructing Holocene paleoenvironments in the arid interior of British Columbia, in much the same way as they do in the southwest United States.Les rats Ă queue touffue s'observent souvent dans les escarpements, les talus rocheux et les cavernes dans les forĂȘts ouvertes de Pseudotsuga menziesii et de Pinus ponderosa de l'intĂ©rieur de la Colombie-Britannique. Des amoncellements de matiĂšres fĂ©cales fossilisĂ©s de N. cinerea recueillis dans deux sites du centre de la Colombie-Britannique ont Ă©tĂ© datĂ©s au radio-carbone et analysĂ©s pour leur contenu en pollen, en macrofossiles de vĂ©gĂ©taux et en restes d'insectes. Le site d'Oregon Jack Creek renferme un amoncellement datĂ© Ă 1150 ± 80 BP (WAT-1764). Les analyses polliniques ont rĂ©vĂ©lĂ© qu'il y avait abondance de Cupressaceae (Juniperus) et de Pinus. Les grains de pollen d'arbustes et d'herbacĂ©es comprennent Artemisia, Fabaceae. Poaceae et Asteraceae. Les principaux macrofossiles de vĂ©gĂ©taux Ă©taient des feuilles de Juniperis scopulorum, des aiguilles de Pseudotsuga menziesii, des graines de Chenopodiaceae, des Ă©pines de Rosa et des folioles o"Artemisia. Les restes de trois genres de colĂ©optĂšres (Cryptophagus, Lathridius et Enicmus) reprĂ©sentent les insectes qui vivaient probablement dans les amoncellements, se nourrissant de la matiĂšre organique en dĂ©composition ou des moisissures. Les restes de Limonius proviennent probablement du sol environnant ou des vĂ©gĂ©taux. Le site de Bull Canyon renferme un amoncellement qui date de 700 ± 80 BP (WAT-1765). Les assemblages de pollen et de vĂ©gĂ©taux ressemblent Ă ceux du site d'Oregon Jack Creek. Les matiĂšres fĂ©cales du rat Ă queue touffue offrent de nouvelles possibilitĂ©s de reconstitution des palĂ©oenvironnements de l'HolocĂšne de la rĂ©gion intĂ©rieure aride de la Colombie-Britannique, un peu comme c'est dĂ©jĂ le cas dans le sud des Etats-Unis.Ratten mit buschigem Schwanz (Neotoma cinerea) findet man oft in den Klippen, Schutthalden und HĂŽhlen in den offenen Pseudotsuga menziesii und Pinus ponderosa WĂ ldern im ganzen lnnern von British Columbia. Fosile N. cinerea FĂąkalien von zwei PlĂątzen in Zentral British Columbia wurden mit Radiokarbon datiert und auf Pollen, pflanzliche Makrofossile und lnsektenspuren untersucht. Der Platz Jack Creek in Oregon enthĂ lt einen Fakalienfund, der auf 1150 ± 80 (WAT-1764) Radiokarbonjahre v.u.Z. datiert wird. Die Pollenanalysen enthullen eine FuIIe von Cupressaceae (Juniperus) und Pinus. Buschund Graspollenarten schliessen Artemisia, Fabaceae, Poaceae und Asteraceae ein. Blatter von Juniperus scopulorum, Nadeln von Pseudotsuga menziesii, Samen von Chenopodiaceae, Dornen von Rosa und BlĂąttchen von Artemisia sind die hauptsĂąchlichen Pflanzenmakrofossile. Die Reste von drei Kaferarten, Cryptophagus, Lathridius und Enicmus reprĂąsentieren Insekten, die mĂŽglicherweise in den FĂąkalien lebten und verwesendes organisches Material Oder Schimmel assen. Limonius-Reste wurden wahrscheinlich in die FĂąkalien von nahegelegenem Erdreich Oder Pflanzenmaterial gebracht. Der Platz Bull Canyon enthĂ lt FĂąkalien, die auf 700 ± 80 (WAT-1765) Jahre v.u.Z. datiert werden. Pollen- und makrofossile Pflanzenansammlungen sind denen des Jack Creek-Platzes von Oregon Ă hnlich. FĂąkalien von Waldratten liefern eine neue Dimension bei der Rekonstruktion der PalĂ oumwelt im HolozĂ n im trockenen lnnern von British Columbia, ganz in derselben Weise, wie sie das schon im Sudwesten der Vereinigten Staaten tun
Effects of Wetland Creation on Breeding Season Bird Use in Boreal Eastern Ontario
Wetland construction has been an effective means of mitigating wetland habitat losses due to agricultural and other activities. However, the type, variety, and age of the habitats created are often critical components in the success of the wetland when the aim is to enhance the bird community. Hilliardton Marsh was constructed as a series of cells between 1993 and 1997 in boreal eastern Ontario to provide waterfowl habitat. We determined habitat change and monitored breeding-season bird use before construction and one year after the last cell was constructed. Wetland construction resulted in dramatic changes to the vegetation and bird communities. The area was transformed into a variety of wetland habitats, but primarily marsh, one of the rarest wetland types in boreal Ontario. Survey stations with moderate habitat change exhibited the greatest change in bird species richness. Total species richness increased 55% from 56 to 87 species, with obligate wetland birds increasing from 3 to 26 species. Rare birds increased from 11 to 27 species, with most as obligate or facultative wetland birds, but also Peregrine Falcon (Falco peregrinus). Bird abundance, as measured by the number of stations where a species was observed, increased significantly for obligate wetland birds. There were no significant losses of species from any bird group, as adjacent upland habitat was preserved. This short-term study has shown that construction of new wetland habitat in boreal eastern Ontario, especially marsh, can significantly increase the numbers of breeding-season birds, including rare species. However, longterm monitoring is required to ensure sustained success of wetland construction projects for birds
Managing shoulder pain in manual wheelchair users:a scoping review of conservative treatment interventions
Objective:To review the literature that has explored conservative treatments for the management of shoulder pain in manual wheelchair users.Methods:Five databases were systematically searched in february 2020 for terms related to shoulder pain and manual wheelchair use. Articles were screened and included if they investigated the conservative treatment of shoulder pain in wheelchair users. Participantsâ physical characteristics, experimental design and primary and secondary outcome measures were extracted from studies. Studies were grouped according to treatment type to identify gaps in the literature and guide future research.Results:The initial search identified 407 articles, of which 21 studies met the inclusion criteria. Exercise-based treatment interventions were most prevalent (nâ=â12). A variety of exercise modalities were employed such as strengthening and stretching (nâ=â7), ergometer training (nâ=â3), Pilates classes (nâ=â1) and functional electrical stimulation (nâ=â1). Only three studies supplemented exercise with an additional treatment type. The Wheelchair Users Shoulder Pain Index was used by 18 studies as the primary measure of shoulder pain. Only seven of these included an objective measure of shoulder function. Participant characteristics varied among studies, and physical activity levels were frequently not reported.Conclusions:Despite the high prevalence of shoulder pain in manual wheelchair users, the number of studies to have explored conservative treatment types is low. Exercise is the most commonly used treatment, which is encouraging as physical inactivity can exacerbate other health conditions. Few studies have adopted interdisciplinary treatment strategies or included objective secondary measures to better understand the mechanisms of pain.<br
Licit and illicit drug policies: a typology
To foster comparison of policy interventions across the various categories of licit and illicit drugs, we develop a typology of policies intended to address drug abuse problems. The principal dimensions of the typology are policy type and intervention channel. While the typology has important limitations, as a mechanism to organize information and stimulate thought it holds the potential to improve understanding of commonalities and distinctions among policies applying to widely discrepant drug problems, both within and across cultures. As such, it could contribute to the development of more effective approaches to grappling with a diverse set of drug policy issues.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73129/1/j.1360-0443.1990.tb03081.x.pd
Shoulder and thorax kinematics contribute to increased power output of competitive handcyclists
Current knowledge on recumbent handbike configuration and handcycling technique is limited. The purpose of this study was to evaluate and compare the upper limb kinematics and handbike configurations of recreational and competitive recumbent handcyclists, during sport specific intensities. Thirteen handcyclists were divided into two significantly different groups based on peak aerobic power output (POpeak) and race experience; competitive (n=7; 5 H3 and 2 H4 classes; POpeak: 247±20W) and recreational (n=6; 4 H3 and 2 H4 classes; POpeak: 198±21 W). Participants performed bouts of exercise at training (50% POpeak), competition (70% POpeak), and sprint intensity while threeâdimensional kinematic data (thorax, scapula, shoulder, elbow and wrist) were collected. Statistical parametric mapping was used to compare the kinematics of competitive and recreational handcyclists. Handbike configurations were determined from additional markers on the handbike. Competitive handcyclists flexed their thorax (~5°, P<0.05), extended their shoulder (~10°, P<0.01) and posteriorly tilted their scapular (~15°, P<0.05) more than recreational handcyclists. Differences in scapular motion occurred only at training intensity while differences in shoulder extension and thorax flexion occurred both at training and competition intensities. No differences were observed during sprinting. No significant differences in handbike configuration were identified. This study is the first to compare the upper limb kinematics of competitive recreational handcyclists at sportâspecific intensities. Competitive handcyclists employed significantly different propulsion strategies at training and competition intensities. Since no differences in handbike configuration were identified, these kinematic differences could be due to technical training adaptations potentially optimising muscle recruitment or force generation of the arm
Why Teach? Exploring the Motivations and Expectations of First-year, Alternatively Certified Agriscience Teachers
School-Based agricultural education increasingly depends upon alternatively certified (AC) teachers to teach agriculture across the United States. Understanding why these individuals become teachers is an important step to better recruit and retain educators who do not complete traditional preparation programs. The purpose of our study was to explore the backgrounds, motivations, and expectations of AC agriscience teachers joining the profession. Our study was guided by the social cognitive career theory and utilized a qualitative phenomenological approach. We interviewed seven AC agriscience teachers in Florida during their first-year teaching to explore their journey into teaching agricultural education. Six major themes were found, including background and interest in agriculture, positive teaching self-efficacy expectations, positive teaching outcome expectations, right location and right time, exciting but challenging, and more than expected. We recommend providing support programs tailored for AC agriscience teachers that are guided by the similar backgrounds, motivations, and expectations of AC teachers
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