182 research outputs found
Some Aspects of the Hydrology of the Fraser River Basin, British Columbia
A simple computational procedure for calculating the water balance in the Fraser River basin in British Columbia is presented. The computational model uses readily available meteorological records and is based on the definitional equality that, for a given year, runoff is equal to the difference between precipitation and evapotranspiration adjusted for basin storage fluctuation. The annual hydrologic record generated by this model indicates that, for the period 1951 to 1976, precipitation basin runoff, and evapotranspiration, respectively averaged 737 mm, 433 mm and 301 mm per year, while the mean annual temperature for the same period was 2.1°C. The relationships among the hydrologic components and basin temperature are discussed. It is concluded that, given the known errors in the computational model, the measured water balance is not inconsistent with that derived from the estimating procedure of Thornthwaite and Mather.
 
Drainage Basin Morphometry and River Network Analysis: A Review and Synthesis
This discussion paper is a review of drainage basin morphometry and river network analysis. It is essentially an assemblage of techniques which have become both an important part of geomorphology ahd a useful set of morphometric inputs to hydrologic models of river basins. The paper also provides a discussion of the ideas which collectively have become known as the theory of dynamic equilibrium. It is interesting that many of the concepts and techniques which grew out of this theory have been incorporated into the conventional discipline while the original conceptual framework has become somewhat suspect
River Channel Dynamics: Retrospect and Prospect
This paper attempts to define the state of the art in the field of channel dynamics, to identify critical problem areas, and to suggest the directions of future research. Although the manner in which rivers change the form and pattern of their channels in response to environmental change has been a recurring theme in river studies, it recently has enjoyed considerably increased attention from earth scientists. Perhaps the most significant recent evidence of this interest is the appearance of several collected works and reviews of studies of channel changes (for example, see Gregory, 1977; Gregory and Walling, 1979; Kuprianov and Kopaliani, Park, 1981), and the fact that a Session has been devoted to the topic here Second International Conference on Fluvial Sediments at Keele, England, in September 1981. The study of river channel changes, in the broadest sense of the term, is no less than the study of equilibrium channel behaviour and the nature of excursions from those equilibrium conditions. As such it includes almost all that we know about the fluid mechanics and morphology of alluvial channels. But in a more narrow sense of the term it is the collection of empirical and theoretical studies concerned with adjustment of channel cross-sectiondl size, form, and pattern, to shifts in environmental conditions, particularly those that promote changes in discharge and in sediment loads. In a still narrower sense, channel changes may be regarded as have been induced by the activities of human beings
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To the sentence and beyond: a single case therapy report for mild aphasia
Background: Mild aphasia has received limited attention in the research literature, with few published treatment studies despite significant disruption of communication reported by affected individuals. This includes difficulty understanding and producing grammatically complex language, and consequent discourse and/or conversational difficulties. The limited research may be due to a lack of clarity regarding the deficits underlying the disorder, with linguistic and/or cognitive impairments implicated, as well as limited research and treatment resources being targeted at those with more severe deficits
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A Systematically Conducted Scoping Review of the Evidence and Fidelity of Treatments for Verb Deficits in Aphasia: Verb-in-Isolation Treatments
Purpose: Aphasia research demonstrates increasing interest in the treatment of verb retrieval deficits. This systematically conducted scoping review reports on the level and fidelity of the current evidence for verb treatments; on its effectiveness regarding the production of trained and untrained verbs, functional communication, sentences, and discourse; and on the potential active ingredients. Recommendations to guide clinical decision making and future research are made.
Method: The computerized database search included studies from January 1980 to September 2018. The level of evidence of each study was documented, as was fidelity in terms of treatment delivery, enactment, and receipt. Studies were also categorized according to the treatment methods used.
Results: Thirty-seven studies were accepted into the review, and all but 1 constituted a low level of evidence. Thirty-three studies (89%) described treatment in sufficient detail to allow replication, dosage was poorly reported, and the fidelity of treatment was rarely assessed. The most commonly reported treatment techniques were phonological and semantic cueing in 25 (67.5%) and 20 (54%) studies, respectively. Retrieval of trained verbs improved for 80% of participants, and improvements generalized to untrained verbs for 15% of participants. There was not sufficient detail to evaluate the impact of treatment on sentence production, functional communication, and discourse.
Conclusions: The evidence for verb treatments is predominantly of a low level. There are encouraging findings in terms of treatments being replicable; however, this is tempered by poor monitoring of treatment fidelity. The quality of verb treatment research would be improved by researchers reaching consensus regarding outcome measures (including generalization to, e.g., sentences and discourse) by manualizing treatment to facilitate implementation and exploring the opinions of participants. Finally, while treatment is largely effective in improving production of trained verbs, lack of generalization to untrained items leads to the recommendation that personally relevant verbs are prioritized
Early Postglacial Sedimentation of Lower Seymour Valley, Southwestern British Columbia
In lower Seymour Valley, much of the sediment derived from the erosion of valley-side drift (paraglacial sediments) remains in storage in the form of alluvial fans and aprons. Fluvial incision into these features has exposed sections for lithostratigraphic and chronological study. Radiocarbon dating of organic-rich beds within these deposits indicate that paraglacial sedimentation of lower Seymour Valley commenced before 11.4 ka, was periodic, and was essentially complete by about 9 ka; Seymour River had incised to its present vertical position by about 5 ka. Furthermore, our radiocarbon ages indicate that, although paraglacial sedimentation commenced shortly following deglaciation when the climate was cool and moist, a significant amount of sedimentation occurred during a transition from wet and moist climate to warm and dry (xerothermic) conditions (ca. 10 ka). Charcoal-rich beds indicate that some erosional events may have been a result of slope instability caused by fire.La plus grande partie des sédiments de la vallée résultant de l'érosion latérale des dépôts « paraglaciaires » demeurent accumulés sous forme de cône alluvial ou de plaine alluviale. L'encaissement fluviatile dans ces formes a mis au jour des coupes favorisant les études lithostratigraphiques et chronologiques. La datation au radiocarbone de lits riches en matière organique montre que la sédimentation « paraglaciaire » périodique a commencé avant 11,4 ka et s'est à toutes fins pratiques terminée vers 9 ka dans la vallée. L'encaissement de la Seymour River jusqu'à son niveau actuel était atteint vers 5 ka. De plus, les datations montrent que même si la sédimentation « paraglaciaire » a commencé peu après la déglaciation, alors que le climat était frais et humide, une bonne partie de la sédimentation s'est effectuée au cours d'une période de transition vers un climat chaud et sec (conditions xérothermiques) vers 10ka. Les lits riches en charbon indiquent qu'une certaine partie de l'érosion est attribuable à l'instabilité des pentes occasionnée par les feux
Drainage Basin Hydrology: A Review and Synthesis
This paper is the second of a four-part review and discussion of the basic principles and theories of river behaviour. This discussion paper is a relatively comprehensive review of drainage basin hydrology, although it is intentionally biased towards hydrologic conditions in Canada. For example, the treatment of snowmelt runoff is more detailed than those found in standard texts. Emphasis has also been given to certain topics which are directly relevant to the discussion in other parts of this River Studies series. Throughout this work I have attempted to "translate" the often highly technical discussion into a form that a generalist in the earth sciences would find useful
Aphasia rehabilitation: Does generalisation from anomia therapy occur and is it predictable? A case series study
Introduction: The majority of adults with acquired aphasia have anomia which can respond to rehabilitation with cues. However, the literature and clinical consensus suggest change is usually limited to treated items. We investigated the effect of an experimentally controlled intervention using progressive cues in the rehabilitation of noun retrieval/production in 16 participants with chronic aphasia. Method: Participants were sub-divided relative to the group according to performance on semantic tasks (spoken/written word to picture matching) and phonological output processing (presence/absence of word length effect and proportion of phonological errors in picture naming) in order to investigate outcome in relation to language profile. Cueing therapy took place weekly for 8 weeks. Results: Intervention resulted in significant improvement on naming treated items for 15/16 participants, with stable performance on control tasks. Change occurred at the point of intervention and not during pre-therapy assessments. We predicted particular patterns of generalisation which were upheld. Only participants classified as having relatively less of a semantic difficulty and more of a phonological output deficit demonstrated generalisation to untreated items. Outcome did not relate to traditional aphasia classification. Conclusion: A cueing hierarchy can improve word retrieval/production for adults with aphasia. In some cases generalisation to untreated items also occurs. The study demonstrates that the results of behavioural testing can be used to guide predictions of recovery with intervention. © 2013 Elsevier Ltd
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A Systematically Conducted Scoping Review of the Evidence and Fidelity of Treatments for Verb and Sentence Deficits in Aphasia: Sentence Treatments
Purpose: This review article synthesizes and evaluates the evidence for sentence production treatments in aphasia, systematically charting impairment-based and functional communication outcomes. It reports (a) the level of evidence and fidelity of sentence treatments; (b) the impact of treatment on production of trained and untrained verbs and sentences, functional communication, and discourse; and (c) the potential active ingredients of treatment.
Method: The search included studies from January 1980 to June 2019. The level of evidence of each study was documented, as was fidelity in terms of treatment delivery, enactment, and receipt. Studies were also categorized according to treatment methods used.
Results: Thirty-three studies were accepted into the review and predominantly constituted Level 4 evidence (e.g., case control studies and case series). Thirty studies (90%) described treatment in sufficient detail to allow replication, but dosage was poorly reported, and fidelity of treatment was rarely assessed. The most commonly reported treatment techniques were mapping (10 studies: 30%), predicate argument structure treatment (six studies: 18%), and verb network strengthening treatment (five studies: 15%). Production of trained sentences improved for 83% of participants, and improvements generalized to untrained sentences for 59% of participants. Functional communication was rarely assessed, but discourse production improved for 70% of participants.
Conclusions: The evidence for sentence treatments is predominantly generated from Level 4 studies. Treatments were effective for the majority of participants regarding trained sentence and discourse production. However, there is inconsistent use of statistical analysis to verify improvements, and diverse outcome measures are used, which makes interpretation of the evidence difficult. The quality of sentence treatment research would be improved by agreeing a core set of outcome measures and extended by ascertaining the views of participants on sentence treatments
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A feasibility study of a novel computer-based treatment for sentence production deficits in aphasia, delivered by a combination of clinician-led and self-managed treatment sessions
Background: There is increasing evidence that face-to-face treatments for verb and sentence production deficits in aphasia can be effective. However, very few studies have investigated supplementing such treatments with self-managed computer-based home practice. Given the increasing importance of computer-based aphasia treatment, it is imperative that the feasibility of this mode of delivering verb and sentence treatments is explored.
Aims: This study explored the feasibility and preliminary effectiveness of a novel computer-based treatment for sentence production deficits in aphasia, delivered by a combination of face-to-face and self-managed treatment sessions. The effect of treatment on verb and sentence production, discourse and functional communication was assessed.
Methods & Procedures: The study used a pre-post design with six single cases: three males and three females aged 49 – 81 years. The Sentence Production Treatment (SPT) was developed based on the evidence from systematic reviews of verb-in-isolation and sentence treatments respectively. The SPT was low dose (8 hours) and clinician delivered, supplemented by a minimum set level (16 hours) of self-managed computer-based treatment. The feasibility of the SPT was investigated by: monitoring recruitment and retention of participants; logging any technical issues; assessing the fidelity of face-to-face treatment delivery using checklists; and monitoring compliance with self-delivered treatment.
Outcomes & Results: The SPT was found to be feasible and acceptable to the six participants. Treatment effects were noted on trained verb production and sentence production for five participants each. Generalisation to untrained verb and sentence targets and discourse was more limited, however four participants perceived functional communication improvements.
Conclusions: The study represents the first preliminary evidence that a computer-based sentence level treatment for sentence production deficits in aphasia, which included a self-managed component, is feasible and can be effective. Given these overall positive findings of feasibility and benefit, further feasibility testing is warranted, exploring intervention refinement and candidacy
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