159 research outputs found

    Assessing Threshold Concepts for Information Literacy

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    This presentation was offered as part of the CUNY Library Assessment Conference, Reinventing Libraries: Reinventing Assessment, held at the City University of New York in June 2014

    Near-UV OH Prompt Emission in the Innermost Coma of 103P/Hartley 2

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    The Deep Impact spacecraft fly-by of comet 103P/Hartley 2 occurred on 2010 November 4, one week after perihelion with a closest approach (CA) distance of about 700 km. We used narrowband images obtained by the Medium Resolution Imager (MRI) onboard the spacecraft to study the gas and dust in the innermost coma. We derived an overall dust reddening of 15\%/100 nm between 345 and 749 nm and identified a blue enhancement in the dust coma in the sunward direction within 5 km from the nucleus, which we interpret as a localized enrichment in water ice. OH column density maps show an anti-sunward enhancement throughout the encounter except for the highest resolution images, acquired at CA, where a radial jet becomes visible in the innermost coma, extending up to 12 km from the nucleus. The OH distribution in the inner coma is very different from that expected for a fragment species. Instead, it correlates well with the water vapor map derived by the HRI-IR instrument onboard Deep Impact \citep{AHearn2011}. Radial profiles of the OH column density and derived water production rates show an excess of OH emission during CA that cannot be explained with pure fluorescence. We attribute this excess to a prompt emission process where photodissociation of H2_2O directly produces excited OH*(A2Σ+A^2\it{\Sigma}^+) radicals. Our observations provide the first direct imaging of Near-UV prompt emission of OH. We therefore suggest the use of a dedicated filter centered at 318.8 nm to directly trace the water in the coma of comets.Comment: 21 page

    Enanismo y podredumbre basal de Eustoma grandiflorum y su relación con la densidad de Fusarium solani en el suelo

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    En cultivos comerciales de lisianthus de La Plata y alrededores (Argentina), se observó que Fusarium solani afecta al 100% de los establecimientos productivos provocando enanismo y podredumbre basal. Se realizó un ensayo para analizar la densidad de F. solani del suelo bajo el efecto de distintos tratamientos y relacionarla con la evolución de ambas patologías. Los análisis del suelo se hicieron en 3 épocas: antes del transplante (octubre), al inicio (enero) y al final (marzo) de la floración. En enero y marzo se evaluó la incidencia de cada enfermedad y se cuantificaron las plantas cosechadas. La población de F. solani no varió en las 3 épocas y se redujo significativamente con los fumigantes y el vapor. Esto determinó una incidencia del enanismo (enero) de 0 a 9,5% con los primeros y de 31,4% con el vapor. Para el testigo y los fungicidas la incidencia varió entre el 87,9 y el 100%, disminuyendo las plantas cosechadas. La podredumbre basal comenzó con el ingreso del patógeno a través de las heridas producidas por la cosecha. Ésta fue significativamente mayor con los fumigantes (90,7 a 99%) y también con el vapor (76,8%), produciéndose la mayor incidencia en marzo (15,7 a 22,2 y 10,1% respectivamente), reduciéndose el período productivo. Se destaca la importancia de disminuir la densidad de F. solani en el momento del transplante. Entre los métodos de control el Metam sodio y Dazomet podrían ser eficaces sustitutos del Bromuro de metilo, seguidos por el vapor.Fusarium solani was recorded in 100% of the commercial crops of lisianthus (Eustoma grandiflorum) located around La Plata (Argentina). The pathogen causes stunt and basal rot. A trial was carried out to analyse the F. solani soil density and its relation to the development of both diseases. Soil samples were analysed at three times: before transplant (October), at the beginning of flowering (January) and at the ending of flowering (March) of flowering. The incidence of each disease was evaluated in January and March, and the plants harvested were quantified. The soil density of F. solani was not altered during the three times for each treatment, and fumigants and steam decrease it significantly. In January the stunt incidence reached 0 to 9.5% with the fumigants and 31.4% with the steam treatment. In the control and fungicide plots, the incidence reached 87.9 to 100%, and a consequent reduction of flower production was observed. Stem rot began after the flowers were harvested as a result of pathogen entry through the wounds. The major values of harvested plants were obtained with fumigants (90.7 to 99%) and steam (76.8%), so the greatest stem rot incidence was 15.7 to 22.2 and 10.1%, respectively, in March, and the productive period was shortened. The need of reducing F. solani soil density before lisianthus transplant is emphasized. Among soil control treatments, Metham sodium and Dazomet could be effective substitutes for Methil bromide followed by steam treatment

    Tuning Design Parameters of ICAM-1-Targeted 3DNA Nanocarriers to Optimize Pulmonary Targeting Depending on Drug Type

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    3DNA holds promise as a carrier for drugs that can be intercalated into its core or linked to surface arms. Coupling 3DNA to an antibody targeting intercellular adhesion molecule 1 (ICAM-1) results in high lung-specific biodistributions in vivo. While the role of individual parameters on ICAM-1 targeting has been studied for other nanocarriers, it has never been examined for 3DNA or in a manner capable of revealing the hierarchic interplay among said parameters. In this study, we used 2-layer vs. 4-layer anti-ICAM 3DNA and radiotracing to examine biodistribution in mice. We found that, below saturating conditions and within the ranges tested, the density of targeting antibodies on 3DNA is the most relevant parameter driving lung targeting over liver clearance, compared to the number of antibodies per carrier, total antibody dose, 3DNA dose, 3DNA size, or the administered concentration, which influenced the dose in organs but not the lung specific-over-liver clearance ratio. Data predicts that lung-specific delivery of intercalating (core loaded) drugs can be tuned using this biodistribution pattern, while that of arm-linked (surface loaded) drugs requires a careful parametric balance because increasing anti-ICAM density reduces the number of 3DNA arms available for drug loading

    Water Ice and Dust in the Innermost Coma of Comet 103P/Hartley 2

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    On November 4th, 2010, the Deep Impact eXtended Investigation (DIXI) successfully encountered comet 103P/Hartley 2, when it was at a heliocentric distance of 1.06 AU. Spatially resolved near-IR spectra of comet Hartley 2 were acquired in the 1.05-4.83 micron wavelength range using the HRI-IR spectrometer. We present spectral maps of the inner ~10 kilometers of the coma collected 7 minutes and 23 minutes after closest approach. The extracted reflectance spectra include well-defined absorption bands near 1.5, 2.0, and 3.0 micron consistent in position, bandwidth, and shape with the presence of water ice grains. Using Hapke's radiative transfer model, we characterize the type of mixing (areal vs. intimate), relative abundance, grain size, and spatial distribution of water ice and refractories. Our modeling suggests that the dust, which dominates the innermost coma of Hartley 2 and is at a temperature of 300K, is thermally and physically decoupled from the fine-grained water ice particles, which are on the order of 1 micron in size. The strong correlation between the water ice, dust, and CO2 spatial distribution supports the concept that CO2 gas drags the water ice and dust grains from the nucleus. Once in the coma, the water ice begins subliming while the dust is in a constant outflow. The derived water ice scale-length is compatible with the lifetimes expected for 1-micron pure water ice grains at 1 AU, if velocities are near 0.5 m/s. Such velocities, about three order of magnitudes lower than the expansion velocities expected for isolated 1-micron water ice particles [Hanner, 1981; Whipple, 1951], suggest that the observed water ice grains are likely aggregates.Comment: 51 pages, 12 figures, accepted for publication in Icaru

    Asymmetry in sleep spindles and motor outcome in infants with unilateral brain injury

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    Aim To determine whether interhemispheric difference in sleep spindles in infants with perinatal unilateral brain injury could link to a pathological network reorganization that underpins the development of unilateral cerebral palsy (CP). Method This was a multicentre retrospective study of 40 infants (19 females, 21 males) with unilateral brain injury. Sleep spindles were detected and quantified with an automated algorithm from electroencephalograph records performed at 2 months to 5 months of age. The clinical outcomes after 18 months were compared to spindle power asymmetry (SPA) between hemispheres in different brain regions. Results We found a significantly increased SPA in infants who later developed unilateral CP (n=13, with the most robust interhemispheric difference seen in the central spindles. The best individual-level prediction of unilateral CP was seen in the centro-occipital spindles with an overall accuracy of 93%. An empiric cut-off level for SPA at 0.65 gave a positive predictive value of 100% and a negative predictive value of 93% for later development of unilateral CP. Interpretation Our data suggest that automated analysis of interhemispheric SPA provides a potential biomarker of unilateral CP at a very early age. This holds promise for guiding the early diagnostic process in infants with a perinatally identified brain injury.Peer reviewe

    A Multicentre Database for Normative Brainstem Auditory Evoked Potentials (BAEPs) in Children: Methodology for Data Collection and Evaluation

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    The influence of physiological and methodological factors on recordings of brainstem auditory evoked potentials (BAEPs) is greater in children than in adults. To collect and evaluate BAEP data in normal children, and measure intra- and inter-laboratory variability. Seven hundred and fifty unselected BAEP recordings were collected and evaluated from children ranging from neonates to 14-year-olds by eight laboratories in Italy. In newborns, three laboratories showed satisfactory concordance; wave I was more broadly distributed than wave V and IPL I-V. The evaluation of pooled BAEP data from the older children showed that laboratories with age-matched data gave overlapping results; those with unmatched-age data differed significantly. The sound intensities of the laboratories did not significantly affect absolute BAEP latencies or IPLs. Females had shorter latencies than males; the difference was not significant. A single exponential regression model was an adequate but not the best predictor of normal data. The pooled data were consistent with the physiological maturation of the brainstem acoustic pathway. The BAEPs was reliably normalised using the natural logarithm of age. The differences between Centres were related to sample size, measurement accuracy, and inclusion and selection criteria. The creation of multicentre common database from an unmatched data collection is feasible and reliable enough for clinical diagnosis and multicentre clinical research

    The future of work in shaping the employment inclusion of young adults with disabilities:a qualitative study

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    Purpose: The world of work is changing and creating challenges and opportunities for the employment inclusion of young people with disabilities. In this article, the perceptions held by young adults with disabilities regarding participation in the future of work are examined. Design/methodology/approach: One-on-one interviews were conducted with Canadian young adults (ages 18–36 years) living with a disability. Participants were asked about their thoughts regarding the impact of the changing nature of work on their labor market involvement and career aspirations. A thematic analysis was performed to identify and examine emergent salient themes. Findings: In total, 22 young adults were interviewed; over half held secure employment. Career aspirations and work-related decisions were primarily shaped by a participant's health needs. The future of work was seen as a more proximal determinant to employment. Digital technologies were expected to impact working conditions and create barriers and facilitators to employment. Participants who indicated being securely employed held positive expectations regarding the impact of digital technology on their work. Participants working precariously held negative appraisals regarding the impact of digital technologies on employment opportunities. The role of technological and soft skills was critical to participating in a labor market reliant on advanced technology. Participants reported barriers to developing job skills related to their disability and their work arrangements. Originality/value: This research highlights the importance of considering changes in the future of work, especially the digital transformation of the economy, in the design of initiatives which promote the employment inclusion of young adults with disabilities. Despite the significance of the changing nature of work, supporting health needs and encouraging access to secure work arrangements also remain paramount.</p

    Post-harvest rots of pumpkin (Cucurbita moschata Duch.) “butternut” type. Enzymatic activity of Fusarium spp.

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    El zapallo tipo butternut (C. moschata) es el de mayor consumo en la Argentina. Durante el almacenamiento está expuesto a podredumbres ocasionadas por distintas especies de Fusarium con diferente virulencia. Para establecer alguna correlación entre la patogenicidady la actividad enzimática, con 22 cepas de dichas especies, se evaluó la producción "in vitro" de enzimas pectinolíticas y celulolíticas. Para la determinación se consideró la disminución de la viscosidad que produjo el filtrado de los hongos sobre sus respectivos sustratos. Se comprobó que todas las cepas produjeron ambos grupos de enzimas pero no se pudo establecer la correlación entre la capacidad patogénica de las mismas y su actividad enzimática.The “butternut" type pumpkin (Cucurbita moschata) is the most marketable vegetable in Argentina. Fusarium spp. exhibiting different pathogenicity, cause various rots during storage. Twenty two strains of Fusarium spp. were tested to study pectinolitic and cellulolitic enzymes production. The purpose of this work was to find any correlation between pathogenicity and enzyme activity. It was measured by reading viscosimetrical reduction after filtration of fungi over their corresponding substrate. The results indicated that all the strains, pathogenic and saprophitic, were able to produce both group of enzymes and no correlation was found between pathogenic and enzymatic activity.Facultad de Ciencias Agrarias y Forestale
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