1,564 research outputs found
An application of LANDSAT multispectral imagery for the classification of hydrobiological systems, Shark River Slough, Everglades National Park, Florida
Multivariant hydrologic parameters over the Shark River Slough were investigated. Ground truth was established utilizing U-2 infrared photography and comprehensive field data to define a control network which represented all hydrobiological systems in the slough. These data were then applied to LANDSAT imagery utilizing an interactive multispectral processor which generated hydrographic maps through classification of the slough and defined the multispectral surface radiance characteristics of the wetlands areas in the park. The spectral response of each hydrobiological zone was determined and plotted to formulate multispectral relationships between the emittent energy from the slough in order to determine the best possible multispectral wavelength combinations to enhance classification results. The extent of each hydrobiological zone in slough was determined and flow vectors for water movement throughout the slough established
Grassland invaders and their mycorrhizal symbionts:a study across climate and invasion gradients
Controlled experiments show that arbuscular mycorrhizal fungi (AMF) can increase competitiveness of exotic plants, potentially increasing invasion success. We surveyed AMF abundance and community composition in Centaurea stoebe and Potentilla recta invasions in the western USA to assess whether patterns were consistent with mycorrhizal-mediated invasions. We asked whether (1) AMF abundance and community composition differ between native and exotic forbs, (2) associations between native plants and AMF shift with invading exotic plants, and (3) AMF abundance and/or community composition differ in areas where exotic plants are highly invasive and in areas where they are not. We collected soil and roots from invaded and native forb communities along invasion gradients and in regions with different invasion densities. We used AMF root colonization as a measure of AMF abundance and characterized AMF communities in roots using 454-sequencing of the LSU-rDNA region. All plants were highly colonized (>60%), but exotic forbs tended to be more colonized than natives (P < 0.001). We identified 30 AMF operational taxonomic units (OTUs) across sites, and community composition was best predicted by abiotic factors (soil texture, pH). Two OTUs in the genera Glomus and Rhizophagus dominated in most communities, and their dominance increased with invasion density (r = 0.57, P = 0.010), while overall OTU richness decreased with invasion density (r = â0.61, P = 0.006). Samples along P. recta invasion gradients revealed small and reciprocal shifts in AMF communities with >45% fungal OTUs shared between neighboring native and P. recta plants. Overall, we observed significant, but modest, differences in AMF colonization and communities between co-occurring exotic and native forbs and among exotic forbs across regions that differ in invasion pressure. While experimental manipulations are required to assess functional consequences, the observed patterns are not consistent with those expected from strong mycorrhizal-mediated invasions
From Egypt to Lithuania:Marija RudzinskaitÄ-ArcimaviÄienÄâs Mummy and its Radiological Investigation
Mutation in the V2 vasopressin receptor gene, AVPR2, causes nephrogenic syndrome of inappropriate diuresis
Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is a recently discovered rare disease caused by gain-of-function mutations of the V2 vasopressin receptor gene, AVPR2. To date, mutations of Phe229 and Arg137 have been identified as gain-of-function in the V2 vasopressin receptor (V2R). These receptor mutations lead to hyponatremia, which may lead to clinical symptoms in infants. Here we present a newly identified I130N substitution in exon 2 of the V2R gene in a family, causing NSIAD. This I130N mutation resulted in constitutive activity of the V2R with constitutive cyclic adenosine monophosphate (cAMP) generation in HEK293 cells. This basal activity could be blocked by the inverse agonist tolvaptan and arginine-vasopressin stimulation enhanced the cAMP production of I130N-V2R. The mutation causes a biased receptor conformation as the basal cAMP generation activity of I130N does not lead to interaction with β-arrestin. The constitutive activity of the mutant receptor caused constitutive dynamin-dependent and β-arrestin-independent internalization. The inhibition of basal internalization using dominant-negative dynamin resulted in an increased cell surface expression. In contrast to the constitutive internalization, agonist-induced endocytosis was β-arrestin dependent. Thus, tolvaptan could be used for treatment of hyponatremia in patients with NSIAD who carry the I130N-V2R mutation.Kidney International advance online publication, 1 July 2015; doi:10.1038/ki.2015.181. Š 2015 International Society of Nephrolog
Cone beam computed tomography in the assessment of TMJ deformity in children with JIA: repeatability of a novel scoring system
Background
The temporomandibular joint (TMJ) is frequently involved in juvenile idiopathic arthritis (JIA). Diagnostic imaging is necessary to correctly diagnose and evaluate TMJ involvement, however, hitherto little has been published on the accuracy of the applied scoring systems and measurements. The present study aims to investigate the precision of 20 imaging features and five measurements based on cone beam computed tomography (CBCT).
Methods
Imaging and clinical data from 84 participants in the Norwegian study on juvenile idiopathic arthritis, the NorJIA study, were collected. Altogether 20 imaging features and five measurements were evaluated independently by three experienced radiologists for intra- and interobserver agreement. Agreement of categorical variables was assessed by Fleissâ, Cohenâs simple or weighted Kappa as appropriate. Agreement of continuous variables was assessed with 95% limits of agreement as advised by Bland and Altman.
Results
âOverall impression of TMJ deformityâ showed almost perfect intraobserver agreement with a kappa coefficient of 0.81 (95% CI 0.69â0.92), and substantial interobserver agreement (Fleissâ kappa 0.70 (0.61â0.78)). Moreover, both âflatteningâ and âirregularitiesâ of the eminence/fossa and condyle performed well, with intra- and interobserver agreements of 0.66â0.82 and 0.55â0.76, respectively. âReduced condylar volumeâ and âcontinuityâ of the fossa/eminence had moderate intra- and interobserver Kappa values, whereas continuity of the condyle had Kappa values above 0.55. Measurements of distances and angles had limits of agreement of more than 15% of the sample mean.
Conclusions
We propose a CBCT-based scoring system of nine precise imaging features suggestive of TMJ deformity in JIA. Their clinical validity must be tested.publishedVersio
Cone beam computed tomography in the assessment of TMJ deformity in children with JIA: repeatability of a novel scoring system
Background The temporomandibular joint (TMJ) is frequently involved in juvenile idiopathic arthritis (JIA). Diagâ
nostic imaging is necessary to correctly diagnose and evaluate TMJ involvement, however, hitherto little has been
published on the accuracy of the applied scoring systems and measurements. The present study aims to investigate
the precision of 20 imaging features and fve measurements based on cone beam computed tomography (CBCT).
Methods Imaging and clinical data from 84 participants in the Norwegian study on juvenile idiopathic arthritis,
the NorJIA study, were collected. Altogether 20 imaging features and fve measurements were evaluated indepenâ
dently by three experienced radiologists for intra- and interobserver agreement. Agreement of categorical variables
was assessed by Fleissâ, Cohenâs simple or weighted Kappa as appropriate. Agreement of continuous variables was
assessed with 95% limits of agreement as advised by Bland and Altman.
Results âOverall impression of TMJ deformityâ showed almost perfect intraobserver agreement with a kappa coefâ
fcient of 0.81 (95% CI 0.69â0.92), and substantial interobserver agreement (Fleissâ kappa 0.70 (0.61â0.78)). Moreover,
both âfatteningâ and âirregularitiesâ of the eminence/fossa and condyle performed well, with intra- and interobserver
agreements of 0.66â0.82 and 0.55â0.76, respectively. âReduced condylar volumeâ and âcontinuityâ of the fossa/emiâ
nence had moderate intra- and interobserver Kappa values, whereas continuity of the condyle had Kappa values
above 0.55. Measurements of distances and angles had limits of agreement of more than 15% of the sample mean.
Conclusions We propose a CBCT-based scoring system of nine precise imaging features suggestive of TMJ deformity
in JIA. Their clinical validity must be tested
Revisiting the radiographic assessment of osteoporosis-Osteopenia in children 0-2 years of age. A systematic review
Background
Imaging for osteoporosis has two major aims, first, to identify the presence of low bone mass (osteopenia), and second, to quantify bone mass using semiquantitative (conventional radiography) or quantitative (densitometry) methods. In young children, densitometry is hampered by the lack of reference values, and high-quality radiographs still play a role although the evaluation of osteopenia as a marker for osteoporosis is subjective and based on personal experience. Medical experts questioned in court over child abuse, often refer to the literature and state that 20â40% loss of bone mass is warranted before osteopenia becomes evident on radiographs. In our systematic review, we aimed at identifying evidence underpinning this statement. A secondary outcome was identifying normal references for cortical thickness of the skeleton in infants born term, < 2 years of age.
Methods
We undertook systematic searches in Medline, Embase and Svemed+, covering 1946â2020. Unpublished material was searched in Clinical trials and International Clinical Trials Registry Platform (ICTRP). Both relevant subject headings and free text words were used for the following concepts: osteoporosis or osteopenia, radiography, children up to 6 years.
Results
A total 5592 publications were identified, of which none met the inclusion criteria for the primary outcome; the degree of bone loss warranted before osteopenia becomes visible radiographically. As for the secondary outcome, 21 studies were identified. None of the studies was true population based and none covered the pre-defined age range from 0â2 years. However, four studies of which three having a crossectional and one a longitudinal design, included newborns while one study included children 0â2 years.
Conclusions
Despite an extensive literature search, we did not find any studies supporting the assumption that a 20â40% bone loss is required before osteopenia becomes visible on radiographs. Reference values for cortical thickness were sparse. Further studies addressing this important topic are warranted.publishedVersio
Tumourâeducated macrophages display a mixed polarisation and enhance pancreatic cancer cell invasion
Influenza T-cell Epitope-Loaded Virosomes Adjuvanted with CpG as a Potential Influenza Vaccine
Drug Delivery Technolog
- âŚ