148 research outputs found

    Effects of color and animation on visual short -term memory in computer-environment learning tasks

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    The goals of this research study were to gain a better understanding of the effects of color and animation on visual short-term memory (STM) in computer-environment learning tasks. The research methodology was based on an investigative design that attempted to address weaknesses of previous visual STM research (Klauer & Zhao, 2004) to provide information readily applicable to instructional design and technology. A 3 x 2 x 3 totally-within participants, repeated-measures Factorial Analysis of Variance (ANOVA) design was utilized to investigate limitations on visual short-term memory learning processes in computer-learning environments. Participant scores for accuracy of visual learning tasks and participant latency in responses to visual learning tasks were measured. Findings suggest achromatic color information interferes with visual STM learning tasks in specific contexts. Findings also suggest that the use of animations in visual STM learning tasks may interfere with complex visual STM learning. Numerous questions are raised for further research utilizing experimental designs that focus on visual STM learning tasks in contrast to designs that focus solely on identifying visual STM parameters.;Keywords. Computer aided instruction; Computer based instruction; Double dissociations; Dual coding; Multimedia learning theory; Information processing, Instructional design, Phonological loop, Short-term memory, Visual and spatial short-term memory, Visual stimuli, Visuospatial sketch pad, Working memory

    Conditional Entropy Methods for Period Detection in Variable Stars

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    We consider the use of conditional entropy methods to detect the periods of variable stars. We apply this method to the almost 20,000 Cepheids and RR Lyrae stars in the OGLE III database. Such pulsating stars are very important for establishing the size and age scales in the Universe and the accurate detection of the period is a crucial step.The Conditional Entropy method produces results in very good agreement with existing methods such as Lomb-Scargle, but there are some differences, particularly at short periods. We discuss these differences, mostly in multimodal stars and comment on avenues for future research

    Precision limits of the twin-beam multiband URSULA

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    URSULA is a multiband astronomical photoelectric photometer which minimizes errors introduced by the presence of the atmosphere. It operates with two identical channels, one for the star to be measured and the other for a reference star. After a technical description of the present version of the apparatus, some measurements of stellar sources of different brightness, and in different atmospheric conditions are presented. These measurements, based on observations made with the 91 cm Cassegrain telescope of the Catania Astrophysical Observatory, are used to check the photometer accuracy and compare its performance with that of standard photometers

    Queer Repurposed Artifacts: The State of New York City’s Contemporary West Village Bars

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    In recent years, there has been a shift in queer bar culture in New York City’s West Village, and this thesis aims to explore what these changes are and why they are happening now. How do West Village bars survive when queer populations are forced out? While there are various ways to consider how and what survives in the Village, three variables will be addressed: queer history, or the history queer-identified groups using activism, safety measures, or collaborating with outside sources to secure their rights and overall wellbeing; (post)gentrification, beginning with the 90s when mainstream LGBT groups teamed up with developers and police, and ultimately raised the financial value of the West Village’s real-estate; and (inter)national tourism, or the lengths New York City has taken throughout the years to promote tourism, especially during Pride month to benefit financially. These variables are interconnected to the queer bar, and what I will term ‘queer repurposed artifacts’—or the queer bars in the Village with the deepest roots, such as Stonewall, Henrietta Hudson, and Cubbyhole, who all have altered their business model throughout the years to accommodate the neighborhood, and the city’s, changes. This thesis aims to explore the vast ways bars survive and what these repurposed artifacts represent for the present-day queer bar

    Innovazioni di processo per la produzione di compost di qualità idonei alla conservazione del suolo e alla sostenibilità in agricoltura biologica

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    La tutela della risorsa suolo è tra gli aspetti fondamentali del metodo di produzione biologico. L’applicazione di compost di qualità coniuga la necessità del recupero di materia da scarti organici con l’esigenza di reintegrare il contenuto di sostanza organica dei suoli. Tali premesse sono la base di una ricerca finalizzata alla produzione di compost tramite un sistema innovativo, alla caratterizzazione del prodotto finito e alla realizzazione di prove sperimentali in ambiente confinato e in pieno campo, idonee ad individuare un codice di buona pratica agricola per l’utilizzo del compost in agricoltura biologica. Il protocollo sperimentale ha previsto la produzione di 4 tipi di compost (C1, C2, C3, C4) ottenuti da una miscela di partenza contenente: sansa umida denocciolata (sn), stallatico (st) e residui ligneocellulosici triturati (lc). I compost C1 (C/N=30) e C3 (C/N=45) sono stati ottenuti dalla miscelazione di sn :st: lc nel rapporto 7:1:5 (p/p) e 1:5:5 (p/p). C2 e C4 derivano rispettivamente da C1 e C3 per essiccazione all’aria in strato sottile alla fine della fase di biossidazione accelerata (BA). L’essiccazione è stata effettuata al fine di rallentare le attività microbiche ed i processi di evoluzione della sostanza organica ottenendo matrici a due stadi di maturazione. I parametri di processo monitorati sono stati: umidità, temperatura, pH, e solidi volatili. Ad inizio processo (T0), alla fine della fase di BA (T1) e alla fine della fase di curing (T2), sono stati prelevati campioni rappresentativi dai cumuli per la misurazione dell’indice respirometrico dinamico (IRD). I 4 compost, prodotti presso l’impianto di compostaggio sperimentale IAMB, sono stati applicati su una rotazione biennale farro - cece da granella e su una coltivazione di spinacio, entrambi condotti con metodo di produzione biologico. La fase di BA, della durata di 35 gg per C1 e C2 e 18 gg per C3 e C4, è stata condotta in cassone areato non movimentato. La fase di curing (86 gg per C1 e 65 gg per C3) è stata condotta in cumulo statico. L’umidità è stata controllata settimanalmente e corretta al fine di garantire valori di processo tra 50 e 60%, la temperatura massima raggiunta è stata di 72 °C per C1 e 76 °C per C3. L’IRD, partendo da valori compatibili con i dati di letteratura nella miscela iniziale (T0: 4.171 mgO2 gSV-1 h-1 per C1 e C2; 5.955 mgO2 gSV-1 h-1 per C3 e C4), ha raggiunto livelli di piena stabilità per tutti i materiali già alla fine della fase di BA (T1: 424 mgO2 gSV-1 h-1 per C1e C2 e 789 mgO2 gSV-1 h-1 per C3 e C4). I diversi rapporti C/N e i contributi della matrice sn nelle due miscelazioni hanno comportato differenze nei tempi di processo e negli andamenti dei picchi di temperatura giornalieri, risultando più brevi per C3-C4 rispetto a C1-C2. In attesa dei risultati finali relativi all’applicazione in pieno campo, si ipotizza che il prolungarsi del processo in C1-C3 rispetto a C2-C4 comporterà una diversa disponibilità di elementi nutritivi nelle relative tesi sperimentali per effetto del procedere dei processi di biossidazione ed evoluzione della sostanza organica

    Antitumor effects of table grape extracts

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    Grape (Vitis vinifera L.) is a fruit rich in polyphenols, bioactive compounds able to prevent cancer, reduce tumorigenesis, and influence critical cancer-related pathways. This research shows the main results obtained in our previous works: 1) the characterization of the polyphenolic content and antioxidant activity of two table grape skin extracts (GSEs), Autumn Royal, and Egnatia; 2) the GSEs effects on Caco2 colon cancer cell; 3) the effects of GSEs on the lipid composition and the fluidity of the cell membrane. These in vitro studies suggested that Autumn Royal and Egnatia contain high levels of polyphenols, possess antiproliferative activity on the Caco2 human colon carcinoma cell line and inhibit cell migration by acting on membrane fatty acids composition. Moreover, these results highlighted that the new grape variety Egnatia is an exciting source of phenolic compounds that could interest the food and pharmaceutical industries

    Epidermal Growth Factor Receptor-Mediated Membrane Type 1 Matrix Metalloproteinase Endocytosis Regulates the Transition between Invasive versus Expansive Growth of Ovarian Carcinoma Cells in Three-Dimensional Collagen

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    Abstract The epidermal growth factor receptor (EGFR) is overexpressed in ovarian carcinomas and promotes cellular responses that contribute to ovarian cancer pathobiology. In addition to modulation of mitogenic and motogenic behavior, emerging data identify EGFR activation as a novel mechanism for rapid modification of the cell surface proteome. The transmembrane collagenase membrane type 1 matrix metalloproteinase (MT1-MMP, MMP-14) is a major contributor to pericelluar proteolysis in the ovarian carcinoma microenvironment and is subjected to extensive posttranslational regulation. In the present study, the contribution of EGFR activation to control of MT1-MMP cell surface dynamics was investigated. Unstimulated ovarian cancer cells display caveolar colocalization of EGFR and MT1-MMP, whereas EGFR activation prompts internalization via distinct endocytic pathways. EGF treatment results in phosphorylation of the MT1-MMP cytoplasmic tail, and cells expressing a tyrosine mutated form of MT1-MMP (MT1-MMP-Y 573 F) exhibit defective MT1-MMP internalization. As a result of sustained cell surface MT1-MMP activity, a phenotypic epithelial-mesenchymal transition is observed, characterized by enhanced migration and collagen invasion, whereas growth within three-dimensional collagen gels is inhibited. These data support an EGFR-dependent mechanism for regulation of the transition between invasive and expansive growth of ovarian carcinoma cells via modulation of MT1-MMP cell surface dynamics
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