579 research outputs found

    Agrobacterium-mediated transformation and regeneration of transgenic 'Chancellor' wine grape plants expressing the tfdA gene

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    The establishment of grape vineyards in the Midwestern USA is greatly hampered by the use of the herbicide 2,4-D in grain crop fields. The overall goal of this study was to transform 'Chancellor' with the plant expressible bacterial tfdA gene to make it tolerant to 2,4-D. Embryogenic callus was infected and cocultivated with an Agrobacterium construct (LBA4404: pAL4404::tfdA); transformed callus was selected with kanamycin; kanamycin resistant callus was bulked and transformed cell lines identified by PCR. Three PCRpositive embryogenic callus lines were used to regenerate transgenic plants. Analysis of the plant lines for the presence of the tfdA gene by PCR and southern hybridization confirmed its stable integration in their genomes. Transgenic 'Chancellor' grape plants regenerated from these calli proved to be resistant to up to 10 kg·ha-1 of a commercial ester-formulation of 2,4-D, indicating positive expression of the tfdA gene and affording them protection from 2,4-D injury

    Inhibiting the Thermal Gelation of Copolymer Stabilized Nonaqueous Dispersions and the Synthesis of Full Color PMMA Particles

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    Polymeric particle dispersions have numerous potential applications; currently one of the most relevant is their use as inks in electrophoretic displays. These colloidal particles are synthesized from the appropriate monomer using nonaqueous dispersion (NAD) polymerization in a nonpolar solvent, which requires a stabilizer to control particle size and morphology. We have previously reported the facile synthesis of poly(methyl methacrylate)-block-poly(octadecyl acrylate) (PMMA-b-PODA) by atom transfer radical polymerization (ATRP), and its use in the NAD polymerization of MMA in hexane/dodecane solvent mixtures. Here we report the synthesis of monodisperse PMMA particles in dodecane following a standard “industrial” procedure using these PMMA-b-PODA stabilizers. However, it was observed that the particle suspensions solidified when they were left at temperatures below ?18 °C yet redispersed upon being heated. Differential scanning calorimetry, dynamic light scattering, and rheological studies demonstrated that this thermoresponsive behavior was due to a liquid–gel transition occurring at 17.5 °C as a consequence of the upper critical solution temperature of PODA in dodecane being traversed. Consequently, new copolymers were synthesized by ATRP with an ethylhexyl acrylate (EHA) co-monomer incorporated into the lyophilic (dodecane compatible) block. Dispersions stabilized by these PMMA-b-P(ODA-co-EHA) polymers with high EHA contents exhibited lower gelation temperatures because of the greater solvent compatibility with dodecane. The use of a PMMA65-b-(ODA10-co-EHA45) copolymer stabilizer (with the highest EHA content) gave PMMA dispersions that showed no gelation down to 4 °C and monodisperse cross-linked PMMA particles containing organic dyes (cyan, magenta, red, and black) giving colored particles across the size range of approximately 100–1300 nm

    Rock spectral classes observed by the Spirit Rover’s Pancam on the Gusev Crater Plains and in the Columbia Hills

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    This paper examines the ferrous and ferric iron mineralogy of rocks inferred from 246 visible/near-infrared (430–1010 nm) multispectral observations made by the Mars Exploration Rover Spirit’s Pancam on its traverse from its landing site to its second Winter Haven location. Principal component, correspondence analyses, and a sequential maximum angle convex cone technique were used to identify 14 candidate classes. Spectra from the West Spur of Husband Hill and the Watchtower area had the highest 535 and 601 nm band depths indicating that these areas were more oxidized. Differences in the depth and band center of a near infrared (NIR) absorption feature were observed using 904 nm band depth and 803:904 nm ratio and parameters gauging the 754–864 and 754–1009 nm slopes. Spectra of rocks from the southern flank of Husband Hill had negative 754–1009 nm slopes and a broad NIR absorption consistent with high olivine abundances. Rocks observed on the lower West Spur, at the Cumberland Ridge locale, at the Husband Hill summit, and at the Haskin Ridge locale had deep 904 nm band depths and steep 754–864 nm slopes consistent with greater pyroxene abundances. These observations are consistent with results on iron-bearing mineralogy from Spirit’s Mo¨ssbauer spectrometer. Comparisons of these rock spectral classes with a set of terrestrial analog samples found similarities between the West Spur and Watchtower classes and red hematite-bearing impact melts. Fewer similarities were found in comparisons of the Columbia Hills classes with basaltic hydrovolcanic tephras

    Behavioural activation written self-help to improve mood, wellbeing and quality of life in people with dementia supported by informal carers (PROMOTE): study protocol for a single-arm feasibility study.

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    Background: Increases in life expectancy have resulted in a global rise in dementia prevalence. Dementia is associated with poor wellbeing, low quality of life and increased incidence of mental health difficulties such as, low mood or depression. However, currently there is limited access to evidence-based psychological interventions for people with dementia experiencing low mood and poor wellbeing. Behavioural activation-based self-help, supported by informal carers and guided by mental health professionals, may represent an effective and acceptable solution. Methods/design: The present study is a Phase II (feasibility) single-arm trial informed by the MRC Complex Interventions Research Methods Framework. Up to fifty dementia participant/informal carer dyads will be recruited from a variety of settings including primary care, dementia-specific health settings, and community outreach. People living with dementia will receive behavioural activation based self-help and be supported by their informal carer who has received training in the skills required to support the self-help approach. In turn, during the use of the intervention the informal carer will be guided by mental health professionals to help them work through the materials and problem solve any difficulties. Consistent with the objectives of feasibility studies, outcomes relating to recruitment from different settings, employment of different recruitment methods, attrition, data collection procedures, clinical delivery and acceptability of the intervention will be examined. Clinical outcomes for people with dementia (symptoms of depression and quality of life) and informal carers (symptoms of depression and anxiety, carer burden and quality of life) will be measured pretreatment and at 3 months post-treatment allocation. Discussion: This study will examine the feasibility and acceptability of a novel behavioural activation-based self-help intervention designed to promote wellbeing and improve low mood in people living with dementia, alongside methodological and procedural uncertainties associated with research-related procedures. As determined by pre-specified progression criteria, if research procedures and the new intervention demonstrate feasibility and acceptability, results will then be used to inform the design of a pilot randomised controlled trial (RCT) to specifically examine remaining methodological uncertainties associated with recruitment into a randomised controlled design.This study is collaboratively funded by Cornwall Foundation Partnership Trust, South West Peninsula Academic Health Sciences Network and the University of Exeter

    Spectral, mineralogical, and geochemical variations across Home Plate, Gusev Crater, Mars indicate high and low temperature alteration

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    Over the last ~ 3 years in Gusev Crater, Mars, the Spirit rover observed coherent variations in color, mineralogy, and geochemistry across Home Plate, an ~ 80 m-diameter outcrop of basaltic tephra. Observations of Home Plate from orbit and from the summit of Husband Hill reveal clear differences in visible/near-infrared (VNIR) colors between its eastern and western regions that are consistent with mineralogical compositions indicated by Mössbauer spectrometer (MB) and by Miniature Thermal Emission Spectrometer (Mini-TES). Pyroxene and magnetite dominate the east side, while olivine, nanophase Fe oxide (npOx) and glass are more abundant on the western side. Alpha Particle X-Ray Spectrometer (APXS) observations reveal that eastern Home Plate has higher Si/Mg, Al, Zn, Ni, and K, while Cl and Br are higher in the west. We propose that these variations are the result of two distinct alteration regimes that may or may not be temporally related: a localized, higher temperature recrystallization and alteration of the east side of Home Plate and lower temperature alteration of the western side that produced npOx

    Enhancing Collaborative Practices with Preprofessional Occupational Therapists and Early Childhood Special Education Student Teachers: A Pilot Study

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    This article presents the Collaborative Design Model as a tool for developing collaboration and self-efficacy for preprofessional educators and service providers. As student populations continue to become more diverse, preprofessionals entering the classroom must be prepared to collaborate with colleagues effectively and efficiently to address the variety of needs presented in the classroom. Little research exists on the collaboration among preprofessional teachers and preprofessional occupational therapists. The proposed model provides a method for supporting preprofessionals in collaborating to meet the needs of students at risk for or with disabilities. Initial pilot findings suggest the Collaborative Design Model could potentially increase self-efficacy and collaboration skills for preprofessionals working in the classroom

    Spectral Variability among Rocks in Visible and Near Infrared Multispectral Pancam Data Collected at Gusev Crater: Examinations using Spectral Mixture Analysis and Related Techniques

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    Visible and Near Infrared (VNIR) multispectral observations of rocks made by the Mars Exploration Rover Spirit s Panoramic camera (Pancam) have been analysed using a spectral mixture analysis (SMA) methodology. Scenes have been examined from the Gusev crater plains into the Columbia Hills. Most scenes on the plains and in the Columbia Hills could be modeled as three endmember mixtures of a bright material, rock, and shade. Scenes of rocks disturbed by the rover s Rock Abrasion Tool (RAT) required additional endmembers. In the Columbia Hills there were a number of scenes in which additional rock endmembers were required. The SMA methodology identified relatively dust-free areas on undisturbed rock surfaces, as well as spectrally unique areas on RAT abraded rocks. Spectral parameters from these areas were examined and six spectral classes were identified. These classes are named after a type rock or area and are: Adirondack, Lower West Spur, Clovis, Wishstone, Peace, and Watchtower. These classes are discriminable based, primarily, on near-infrared (NIR) spectral parameters. Clovis and Watchtower class rocks appear more oxidized than Wishstone class rocks and Adirondack basalts based on their having higher 535 nm band depths. Comparison of the spectral parameters of these Gusev crater rocks to parameters of glass-dominated basaltic tuffs indicates correspondence between measurements of Clovis and Watchtower classes, but divergence for the Wishstone class rocks which appear to have a higher fraction of crystalline ferrous iron bearing phases. Despite a high sulfur content, the rock Peace has NIR properties resembling plains basalts

    Opportunity, Geologic and Structural Context of Aqueous Alteration in Noachian Outcrops, Marathon Valley and Rim and Endeavour Crater

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    In its 12th year of exploration and 1600 sols since arrival at the rim of the 22 km-diameter Noachian Endeavour impact crater, Mars Exploration Rover Opportunity traversed from the summit of the western rim segment "Cape Tribulation" to "Marathon Valley", a shallow trough dissecting the rim and the site of strong orbital detection of smectites. In situ analysis of the exposures within Marathon Valley is establishing some of the geologic and geochemical controls on the aqueous alteration responsible for smectite detection known to occur in crater rims throughout Noachian terrains of Mars

    Compositions of Diverse Noachian Lithologies at Marathon Valley, Endeavour Crater Rim, Mars

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    Mars Exploration Rover Opportunity has been exploring Meridiani Planum for 11+ years, and is presently investigating the geology of rim segments of 22 km diameter, Noachian-aged Endeavour crater. The Alpha Particle X-ray Spectrometer has determined the compositions of a pre-impact lithology and impact breccias representing ejecta from the crater. Opportunity is now investigating the head (higher elevation, western end) of Marathon Valley. This valley cuts eastward through the central portion of the Cape Tribulation rim segment and provides a window into the lower stratigraphic record of the rim. At the head of Marathon Valley is a shallow (few 10s of cm), ovoid depression approximately 2736 m in size, named Spirit of Saint Louis, that is surrounded by approximately 20-30 cm wide zone of more reddish rocks (red zone). Opportunity has just entered a region of Marathon Valley that shows evidence for Fe-Mg smectite in Compact Reconnaissance Imaging Spectrometer for Mars spectra indicating areally extensive and distinct lithologic units and/or styles of aqueous alteration. Rocks at the head of Marathon Valley and within Spirit of Saint Louis are breccias (valley-head rocks). In some areas, layering inside Spirit of Saint Louis appears continuous with the rocks outside. The valley-head rocks are of similar, generally basaltic composition. The continuity in composition, texture and layering suggest the valley-head rocks are coeval breccias, likely from the Endeavour impact. These local breccias are similar in non-volatile-element composition to breccias investigated elsewhere on the rim. Rocks within the red zone are like those on either side in texture, but have higher Al, Si and Ge, and lower S, Mn, Fe, Ni and Zn as compared to rocks on either side. The valley-head rocks have higher S than most Endeavour rim breccias, while red zone rocks are like those latter breccias in S. Patches within the rocks outside Spirit of Saint Louis have higher Al, Si and Ge indicating red-zone-style alteration extended beyond the narrow red zone. Rocks on either side of the red zone and patches within it have the multispectral signature (determined by Panoramic Camera) of red hematite indicating an oxidizing environment. The red zone appears to be a thin alteration zone marking the border of Spirit of Saint Louis, but the origin of this morphologic feature remains obscure
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