2,895 research outputs found
SOMETHING OLD SOMETHING NEW: SIXTEENTH CENTURY DEVELOPMENTS IN EMBLEMATICS
Andrea Alciati is considered the first author of an emblem book. He was part of the humanist revolution which altered the form of knowledge and helped inspire the creation of the emblem genre. The visual and literary together symbolize aspects of life that have always already been. This thesis examines how theory has dealt with the genre by reviewing Platonic and Aristotelian symbol theory, impresa theory, contemporary literary theory, and modern emblem scholarship. The emblem’s relationship to classical precursors is considered in order to contextualize the genre. How the emblem was driven by the novel elements of the printing trade and how it formulated a relationship with its readers are analyzed as well. The emblem is an artful reconsideration of prior knowledge which is assigned a novel persona because of its mode of production
Effect of a human-teacher vs. a robot-teacher on human learning a pilot study
Studies about the dynamics of human-robot interactions have increased within the past decade as robots become more integrated into the daily lives of humans. However, much of the research into learning and robotics has been focused on methods that would allow robots to learn from humans and very little has been done on how and what, if possible, humans could learn from programmed robots. A between-subjects experiment was conducted, in which two groups were compared: a group where the participants learned a simple pick-and-place block task via video of a human-teacher and a group where the participants learned the same pick-and-place block task via video from a robotic-teacher. After being the taught the task, the participants performed a 15-minute distracter task and then were timed in their reconstruction of the block configuration. An exit survey asking about their level of comfort learning from robot and computer entities was given upon completion. Results showed that there was no significant difference in the rebuild scores of the two groups, but there was a marginally significant difference in the rebuild times of the two groups. Exit survey results, research implications, and future work are discussed
Hijacking membrane transporters for arsenic phytoextraction
Arsenic is a toxic metalloid and recognized carcinogen. Arsenate and arsenite are the most common arsenic species available for uptake by plants. As an inorganic phosphate (Pi) analog, arsenate is acquired by plant roots through endogenous Pi transport systems. Inside the cell, arsenate is reduced to the thiol-reactive form arsenite. Glutathione (GSH)-conjugates of arsenite may be extruded from the cell or sequestered in vacuoles by members of the ATP-binding cassette (ABC) family of transporters. In the present study we sought to enhance both plant arsenic uptake through Pi transporter overexpression, and plant arsenic tolerance through ABC transporter overexpression. We demonstrate that Arabidopsis thaliana plants overexpressing the high-affinity Pi transporter family members, AtPht1;1 or AtPht1;7, are hypersensitive to arsenate due to increased arsenate uptake. These plants do not exhibit increased sensitivity to arsenite. Co-overexpression of the yeast ABC transporter YCF1 in combination with AtPht1;1 or AtPht1;7 suppresses the arsenate-sensitive phenotype while further enhancing arsenic uptake. Taken together, our results support an arsenic transport mechanism in which arsenate uptake is increased through Pi transporter overexpression, and arsenic tolerance is enhanced through YCF1-mediated vacuolar sequestration. This work substantiates the viability of coupling enhanced uptake and vacuolar sequestration as a means for developing a prototypical engineered arsenic hyperaccumulator. © 2012 Elsevier B.V
Project Passport: An Integrated Group-Centered Approach Targeting Pregnant Teens and Their Partners
Objective: To describes the development of Project Passport, a perinatal intervention designed to reduce negative outcomes among pregnant teens. Methods: A logic model guided the planning, development and evaluation plan for the intervention. It included the selection of health goals, behaviors to be targeted, determinants of the selected behaviors, and activities to impact each selected determinant. Results: The process resulted in the formulation of an intervention that incorporates CenteringPregnancy, a group model of prenatal care, Positive Youth Development components, and male involvement. The evaluation examines the effectiveness of the intervention in enhancing health, educational and psychosocial outcomes among pregnant adolescents. Conclusions: The present program was designed to address an important gap in evidence-based interventions targeting pregnant adolescents and their partners
Exploring young people's and youth workers' experiences of spaces for ‘youth development’: creating cultures of participation
The paper focuses on the emergence of ‘positive youth development’ and its impact on older, more established practices of working with young people, such as youth work. Drawing on ethnographic fieldwork in England between 2004 and 2006, in particular young people's and youth workers' accounts of participating in youth work, the analysis engages with the social spaces in which youth work takes place and asks key questions about why young people might participate in youth spaces, what they get out of participating and how such spaces can promote cultures of participation. The analysis shows that such spaces provide young people and their communities with biographical continuity and time becomes a key component for sustaining such spaces. The argument is made for a more nuanced understanding of what young people get out of their participation in youth spaces, and for an epistemological approach to youth praxis that embraces the messiness and inequalities of lived experience
The Lamprey Genome: Illuminating Genomic Change across Eons and Embryogenesis
The lamprey genome provides unique insights into both the deep evolutionary history of vertebrate genomes and the maintenance of genome structure/integrity over development. The lamprey lineage diverged from all other vertebrates approximately 500 million years ago. As such, comparisons between lamprey and other vertebrates permit reconstruction of ancient duplication and rearrangement events that defined the fundamental architecture and gene content of all extant vertebrate genomes. Lamprey also undergoes programmatic changes genome structure that result in the physical elimination of ~20% of its genomic DNA (~0.5Gb from a ~2 Gb genome) from all somatic cell lineages during early embryonic development. Here, we outline recent progress in assembly and analysis of the lamprey germline genome, and progress in the development of methods for characterizing the cellular events that mediate DNA elimination. We have integrated information from several sampling approaches and sequencing technologies to achieve a highly contiguous assembly of lamprey genome (including: Illumina fragments/mate pairs, 20X coverage in Pacific Biosciences reads, dense meiotic maps and optical mapping data). This genome assembly has dramatically improved our ability to dissect the molecular basis and genetic outcomes of programmed genome rearrangements (PGRs), and has improved our understanding of the tempo and mode of large-Âscale duplications and translocations within the ancestral vertebrate lineage. Analysis of the germline genome identifies several genes that are expressed in germline but physically eliminated from all somatic tissues. These eliminated genes correspond to several known oncogenes and appear to identify several other novel oncogene candidates. Complementing this assembly, the development of approaches to in situ analysis of 3D preserved cells has revealed that PGR unfolds through a series of dramatic cellular events that involve the programmatic alteration of several fundamental mechanisms of genome maintenance, including: alignment of chromosomes at metaphase, chromatid cohesion, separation and segregation, and nuclear envelope formation
Genetic Characterization of H3N2 Influenza Viruses Isolated from Pigs in North America, 1977–1999: Evidence for Wholly Human and Reassortant Virus Genotypes
Since 1998, H3N2 viruses have caused epizootics of respiratory disease in pigs throughout the major swine production regions of the U.S. These outbreaks are remarkable because swine influenza in North America had previously been caused almost exclusively by H1N1 viruses. We sequenced the full-length protein coding regions of all eight RNA segments from four H3N2 viruses that we isolated from pigs in the Midwestern U.S. between March 1998 and March 1999, as well as from H3N2 viruses recovered from a piglet in Canada in January 1997 and from a pig in Colorado in 1977. Phylogenetic analyses demonstrated that the 1977 Colorado and 1997 Ontario isolates are wholly human influenza viruses. However, the viruses isolated since 1998 from pigs in the Midwestern U.S. are reassortant viruses containing hemagglutinin, neuraminidase and PB1 polymerase genes from human influenza viruses, matrix, non-structural and nucleoprotein genes from classical swine viruses, and PA and PB2 polymerase genes from avian viruses. The HA proteins of the Midwestern reassortant swine viruses can be differentiated from those of the 1995 lineage of human H3 viruses by 12 amino acid mutations in HA1. In contrast, the Sw:ONT:97 virus, which did not spread from pig-to-pig, lacks 11 of these changes
Population-average mediation analysis for zero-inflated count outcomes
Mediation analysis is an increasingly popular statistical method for
explaining causal pathways to inform intervention. While methods have
increased, there is still a dearth of robust mediation methods for count
outcomes with excess zeroes. Current mediation methods addressing this issue
are computationally intensive, biased, or challenging to interpret. To overcome
these limitations, we propose a new mediation methodology for zero-inflated
count outcomes using the marginalized zero-inflated Poisson (MZIP) model and
the counterfactual approach to mediation. This novel work gives
population-average mediation effects whose variance can be estimated rapidly
via delta method. This methodology is extended to cases with exposure-mediator
interactions. We apply this novel methodology to explore if diabetes diagnosis
can explain BMI differences in healthcare utilization and test model
performance via simulations comparing the proposed MZIP method to existing
zero-inflated and Poisson methods. We find that our proposed method minimizes
bias and computation time compared to alternative approaches while allowing for
straight-forward interpretations.Comment: 34 pages, 2 figures, 4 tables, 49 pages of Supplemental material, 2
supplemental figure
SLS Block 1-B and Exploration Upper Stage Navigation System Design
The SLS Block 1B vehicle is planned to extend NASA's heavy lift capability beyond the initial SLS Block 1 vehicle. The most noticeable change for this vehicle from SLS Block 1 is the swapping of the upper stage from the Interim Cryogenic Propulsion stage (ICPS), a modified Delta IV upper stage, to the more capable Exploration Upper Stage (EUS). As the vehicle evolves to provide greater lift capability and execute more demanding missions so must the SLS Integrated Navigation System to support those missions. The SLS Block 1 vehicle carries two independent navigation systems. The responsibility of the two systems is delineated between ascent and upper stage flight. The Block 1 navigation system is responsible for the phase of flight between the launch pad and insertion into Low-Earth Orbit (LEO). The upper stage system assumes the mission from LEO to payload separation. For the Block 1B vehicle, the two functions are combined into a single system intended to navigate from ground to payload insertion. Both are responsible for self-disposal once payload delivery is achieved. The evolution of the navigation hardware and algorithms from an inertial-only navigation system for Block 1 ascent flight to a tightly coupled GPS-aided inertial navigation system for Block 1-B is described. The Block 1 GN&C system has been designed to meet a LEO insertion target with a specified accuracy. The Block 1-B vehicle navigation system is designed to support the Block 1 LEO target accuracy as well as trans-lunar or trans-planetary injection accuracy. This is measured in terms of payload impact and stage disposal requirements. Additionally, the Block 1-B vehicle is designed to support human exploration and thus is designed to minimize the probability of Loss of Crew (LOC) through high-quality inertial instruments and Fault Detection, Isolation, and Recovery (FDIR) logic. The preliminary Block 1B integrated navigation system design is presented along with the challenges associated with meeting the design objectives. This paper also addresses the design considerations associated with the use of Block 1 and Commercial Off-the-Shelf (COTS) avionics for Block 1-B/EUS as part of an integrated vehicle suite for orbital operations
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