598 research outputs found
Mixture of Kernels and Iterated Semidirect Product of Diffeomorphisms Groups
In the framework of large deformation diffeomorphic metric mapping (LDDMM),
we develop a multi-scale theory for the diffeomorphism group based on previous
works. The purpose of the paper is (1) to develop in details a variational
approach for multi-scale analysis of diffeomorphisms, (2) to generalise to
several scales the semidirect product representation and (3) to illustrate the
resulting diffeomorphic decomposition on synthetic and real images. We also
show that the approaches presented in other papers and the mixture of kernels
are equivalent.Comment: 21 pages, revised version without section on evaluatio
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Ecotones in a changing environment: Workshop on ecotones and global change
The Scientific Committee on Problems of the Environment (SCOPE) has organized an international project to synthesize and advance current theory on the influence of ecotones, or transition zones between ecosystems, on biodiversity and flows of energy, nutrients, water, and project is other materials between ecosystems. In particular, the entire project is designed to evaluate the influence of global climate change and land-use practices on biodiversity and ecological flows associated with ecotones, and will assess the feasibility of monitoring ecotones as early indicators of global change. The later stages of the project will recommend landscape management strategies for ecotones that produce desirable patterns of biodiversity and ecological flows. The result of the project--a comprehensive body of information on the theory and management of biodiversity and ecological flows associated with ecotones--will be part of the planning for research to be carried out under the International Geosphere-Biosphere Program
Parental Abuse, Risky Behavior and Psychopathic Traits in Adolescents and Early Adults
This study examines the associations between parental abuse, risky behavior, and affective psychopathic traits. Ninety-one (49% males) rural adolescents and young adults (between the ages of fourteen and twenty-five) participated in an investigation of gene and environment interactions. The sample consisted of high school and undergraduate college students. These participants provided self-reports of parental abuse, risky behaviors, and psychopathic affective traits. Results suggested that psychopathic traits, especially a lack of remorse and parental abuse, independently account for some risky behavior.https://digitalcommons.mtech.edu/urp_aug_2013/1001/thumbnail.jp
Writing composition ability and spelling competence in deaf subjects: a psycholinguistic analysis of source of difficulties
We studied the compositional written skills and spelling competence of individuals with a severe hearing impairment, examining qualitative and quantitative characteristics of their texts, the psycholinguistic variables modulating their productions, and writing errors following a fine-grained analysis. Sixteen deaf young adults, educated in bilingual settings, were examined and compared to a group of control hearing subjects matched for gender, age, and education. Writing skills were examined through both written composition and written picture-naming tasks. Concerning compositional skills, deaf participants produced shorter and less informative texts, with fewer adjectives and subordinates, and were qualitatively worse with respect to texts produced by hearing controls. Words produced by deaf participants were those acquired earlier and facilitated by a higher lexical neighbourhood. Errors were mainly semantic, morphological, and syntactic errors, reflecting general linguistic weakness. Spelling errors were few, with phonologically nonplausible misspellings relative to controls, and with phonologically plausible ones being quite rare. In the picture-naming task, deaf people had a greater number of all types of errors with respect to their text, including semantic and morphological errors. Their spelling performance featured mainly phonologically nonplausible misspellings, while phonologically plausible ones were relatively few and comparable to controls. Overall, the writing of deaf adults reveal limitations in grammar and lexical-sematic linguistic competence. This was associated with spelling deficits characterized mainly by the poorer use of phonological sublexical spelling procedures. However, in an ecologic context, their spelling deficits appear not so important as has been claimed in the literature
Interpreting forest and grassland biome productivity utilizing nested scales of image resolution and biogeographical analysis
Several hardware, software, and data collection problems encountered were conquered. The Geographic Information System (GIS) data from other systems were converted to ERDAS format for incorporation with the image data. Statistical analysis of the relationship between spectral values and productivity is being pursued. Several project sites, including Jackson, Pope, Boulder, Smokies, and Huntington Forest are evolving as the most intensively studied areas, primarily due to availability of data and time. Progress with data acquisition and quality checking, more details on experimental sites, and brief summarizations of research results and future plans are discussed. Material on personnel, collaborators, facilities, site background, and meetings and publications of the investigators are included
The International Long Term Ecological Research Network: a platform for collaboration
Many scientists around the world became interested in the U.S. Long Term Ecological Research (U.S. LTER) Network\u27s research model during the 1990s and began to develop LTER and Long Term Socio-ecological Research networks in their own countries. These local networks, including the U.S. LTER Network, were loosely federated in 1993 to form the International Long Term Ecological Research (ILTER) Network, a ânetwork of networks.â Although the first 10 yr of ILTER Network activities were largely supported by funds from the U.S. National Science Foundation, the ILTER Network had transformed into a robust, self-sustaining entity by 2006 following a two-year strategic planning process. The goal of the ILTER Network is to improve understanding of how pressures such as climate change and land use affect global ecosystems in order to inform solutions to current and future environmental problems. To fulfill this mission, the ILTER Network fosters collaborations among member scientists to extend the scope of their research across disciplinary boundaries and across more of the ILTER\u27s 600+ research sites. The ILTER Network also has many long-term data sets that are freely available for use by students, scientists, and policymakers all over the world. In this collection of papers, we consider how the ILTER Network has been, and will be, leveraged by U.S. researchers to advance understanding of ecological and socio-ecological systems around the globe
Interpreting forest and grassland biome productivity utilizing nested scales of image resolution and biogeographical analysis
Data acquisition, initial site characterization, image and geographic information methods available, and brief evaluations of first-year for NASA's Thematic Mapper (TM) working group are presented. The TM and other spectral data are examined in order to relate local, intensive ecosystem research findings to estimates of carbon cycling rates over wide geographic regions. The effort is to span environments ranging from dry to moist climates and from good to poor site quality using the TM capability, with and without the inclusion of geographic information system (GIS) data, and thus to interpret the local spatial pattern of factors conditioning biomass or productivity. Twenty-eight TM data sets were acquired, archived, and evaluated. The ERDAS image processing and GIS system were installed on the microcomputer (PC-AT) and its capabilities are being investigated. The TM coverage of seven study areas were exported via ELAS software on the Prime to the ERDAS system. Statistical analysis procedures to be used on the spectral data are being identified
Influence of temporal lobe epilepsy and temporal lobe resection on olfaction
Although temporal lobe epilepsy (TLE) and resection (TLR) impact olfactory eloquent brain structures, their influences on olfaction remain enigmatic. We sought to more definitively assess the influences of TLE and TLR using three well-validated olfactory tests and the testsâ associations with the volume of numerous temporal lobe brain structures. The University of Pennsylvania Smell Identification Test and an odor detection threshold test were administered to 71 TLE patients and 71 age- and sex-matched controls; 69 TLE patients and controls received an odor discrimination/ memory test. Fifty-seven patients and 57 controls were tested on odor identification and threshold before and after TLR; 27 patients and 27 controls were similarly tested for odor detection/discrimination. Scores were compared using analysis of variance and correlated with pre- and post-operative volumes of the target brain structures. TLE was associated with bilateral deficits in all test measures. TLR further decreased function on the side ipsilateral to resection. The hippocampus and other structures were smaller on the focus side of the TLE subjects. Although post-operative volumetric decreases were evident in most measured brain structures, modest contralateral volumetric increases were observed in some cases. No meaningful correlations were evident pre- or post-operatively between the olfactory test scores and the structural volumes. In conclusion, we demonstrate that smell dysfunction is clearly a key element of both TLE and TLR, impacting odor identification, detection, and discrimination/memory. Whether our novel finding of significant post-operative increases in the volume of brain structures contralateral to the resection side reflects plasticity and compensatory processes requires further study
'Pedestrian falls' as necessary addition to the current definition of traffic crashes for improved public health policies
Evaluation of early and late presentation of patients with ocular mucous membrane pemphigoid to two major tertiary referral hospitals in the United Kingdom
PURPOSE: Ocular mucous membrane pemphigoid (OcMMP) is a sight-threatening autoimmune disease in which referral to specialists units for further management is a common practise. This study aims to describe referral patterns, disease phenotype and management strategies in patients who present with either early or established disease to two large tertiary care hospitals in the United Kingdom.\ud
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PATIENTS AND METHODS: In all, 54 consecutive patients with a documented history of OcMMP were followed for 24 months. Two groups were defined: (i) early-onset disease (EOD:<3 years, n=26, 51 eyes) and (ii) established disease (EstD:>5 years, n=24, 48 eyes). Data were captured at first clinic visit, and at 12 and 24 months follow-up. Information regarding duration, activity and stage of disease, visual acuity (VA), therapeutic strategies and clinical outcome were analysed.\ud
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RESULTS: Patients with EOD were younger and had more severe conjunctival inflammation (76% of inflamed eyes) than the EstD group, who had poorer VA (26.7%=VA<3/60, P<0.01) and more advanced disease. Although 40% of patients were on existing immunosuppression, 48% required initiation or switch to more potent immunotherapy. In all, 28% (14) were referred back to the originating hospitals for continued care. Although inflammation had resolved in 78% (60/77) at 12 months, persistence of inflammation and progression did not differ between the two phenotypes. Importantly, 42% demonstrated disease progression in the absence of clinically detectable inflammation.\ud
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CONCLUSIONS: These data highlight that irrespective of OcMMP phenotype, initiation or escalation of potent immunosuppression is required at tertiary hospitals. Moreover, the conjunctival scarring progresses even when the eye remains clinically quiescent. Early referral to tertiary centres is recommended to optimise immunosuppression and limit long-term ocular damage.\ud
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