592 research outputs found
Use of SketchBook Pro with Tablet PC (TabSketch™) as a design thinking tool in the teaching and learning of design and technology
This paper shares the preliminary findings from the first two
phases of an exploratory study on the potential of Tab-Sketch™
as i) a design-thinking tool for design and technology (D&T)
teachers and pupils in secondary schools; ii) a teaching and
learning tool for D&T teachers; and iii) a platform to document
design-thinking in the form of digital design journal. Tab-Sketch
is an acronym derived from Tablet PC and SketchBook Pro, a
computer software. The study, which is naturalistic in approach,
was initiated in Nov 2004 and has evolved into three phases.
Phases 1 and 2 were completed. Phase 3 has commenced in
Aug 2006 and will end in Dec 2007. The insights and
experiences gained from the first two phases include:
• the concept of ‘growing ideas’ conveniently and
dynamically;
• the potential of the software for quick sketches and editing
via features like layer and the range of rendering tools
available;
• Tab-Sketch as a tool for the teacher-designer to dialogue
with self and to practise rapid visualisation;
• capturing design conversations graphically and digitally
between teacher and pupil; and
• ease in manipulating images and ideating presentation
drawings.
These preliminary findings have shaped Phase 3 of the study
which is still on-going
Anomalous morphology in left hemisphere motor and premotor cortex of children who stutter
Stuttering is a neurodevelopmental disorder that affects the smooth flow of speech production. Stuttering onset occurs during a dynamic period of development when children first start learning to formulate sentences. Although most children grow out of stuttering naturally, ∼1% of all children develop persistent stuttering that can lead to significant psychosocial consequences throughout one’s life. To date, few studies have examined neural bases of stuttering in children who stutter, and even fewer have examined the basis for natural recovery versus persistence of stuttering. Here we report the first study to conduct surface-based analysis of the brain morphometric measures in children who stutter. We used FreeSurfer to extract cortical size and shape measures from structural MRI scans collected from the initial year of a longitudinal study involving 70 children (36 stuttering, 34 controls) in the 3–10-year range. The stuttering group was further divided into two groups: persistent and recovered, based on their later longitudinal visits that allowed determination of their eventual clinical outcome. A region of interest analysis that focused on the left hemisphere speech network and a whole-brain exploratory analysis were conducted to examine group differences and group × age interaction effects. We found that the persistent group could be differentiated from the control and recovered groups by reduced cortical thickness in left motor and lateral premotor cortical regions. The recovered group showed an age-related decrease in local gyrification in the left medial premotor cortex (supplementary motor area and and pre-supplementary motor area). These results provide strong evidence of a primary deficit in the left hemisphere speech network, specifically involving lateral premotor cortex and primary motor cortex, in persistent developmental stuttering. Results further point to a possible compensatory mechanism involving left medial premotor cortex in those who recover from childhood stuttering.This study was supported by Award Numbers R01DC011277 (SC) and R01DC007683 (FG) from the National Institute on Deafness and other Communication Disorders (NIDCD). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIDCD or the National Institutes of Health. (R01DC011277 - National Institute on Deafness and other Communication Disorders (NIDCD); R01DC007683 - National Institute on Deafness and other Communication Disorders (NIDCD))Accepted manuscrip
Star Formation History and Chemical Evolution of the Sextans Dwarf Spheroidal Galaxy
We present the star formation history and chemical evolution of the Sextans
dSph dwarf galaxy as a function of galactocentric distance. We derive these
from the photometry of stars in the field using the SMART
model developed by Yuk & Lee (2007, ApJ, 668, 876) and adopting a closed-box
model for chemical evolution. For the adopted age of Sextans 15 Gyr, we find
that 84% of the stars formed prior to 11 Gyr ago, significant star formation
extends from 15 to 11 Gyr ago ( 65% of the stars formed 13 to 15 Gyr ago
while 25% formed 11 to 13 Gyr ago), detectable star formation continued
to at least 8 Gyr ago, the star formation history is more extended in the
central regions than the outskirts, and the difference in star formation rates
between the central and outer regions is most marked 11 to 13 Gyr ago. Whether
blue straggler stars are interpreted as intermediate age main sequence stars
affects conclusions regarding the star formation history for times 4 to 8 Gyr
ago, but this is at most only a trace population. We find that the metallicity
of the stars increased rapidly up to [Fe/H]=--1.6 in the central region and to
[Fe/H]=--1.8 in the outer region within the first Gyr, and has varied slowly
since then. The abundance ratios of several elements derived in this study are
in good agreement with the observational data based on the high resolution
spectroscopy in the literature. We conclude that the primary driver for the
radial gradient of the stellar population in this galaxy is the star formation
history, which self-consistently drives the chemical enrichment history.Comment: 36 pages, 14 figures, To appear in the ApJ, 200
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Co-targeting RNA Polymerases IV and V Promotes Efficient De Novo DNA Methylation in Arabidopsis.
The RNA-directed DNA methylation (RdDM) pathway in plants controls gene expression via cytosine DNA methylation. The ability to manipulate RdDM would shed light on the mechanisms and applications of DNA methylation to control gene expression. Here, we identified diverse RdDM proteins that are capable of targeting methylation and silencing in Arabidopsis when tethered to an artificial zinc finger (ZF-RdDM). We studied their order of action within the RdDM pathway by testing their ability to target methylation in different mutants. We also evaluated ectopic siRNA biogenesis, RNA polymerase V (Pol V) recruitment, targeted DNA methylation, and gene-expression changes at thousands of ZF-RdDM targets. We found that co-targeting both arms of the RdDM pathway, siRNA biogenesis and Pol V recruitment, dramatically enhanced targeted methylation. This work defines how RdDM components establish DNA methylation and enables new strategies for epigenetic gene regulation via targeted DNA methylation
Associations among Human-Associated Fecal Contamination, Microcystis aeruginosa, and Microcystin at Lake Erie Beaches
Lake Erie beaches exhibit impaired water quality due to fecal contamination and cyanobacterial blooms, though few studies address potential relationships between these two public health hazards. Using quantitative polymerase chain reaction (qPCR), Microcystis aeruginosa was monitored in conjunction with a human-associated fecal marker (Bacteroides fragilis group; g-Bfra), microcystin, and water quality parameters at two beaches to evaluate their potential associations. During the summer of 2010, water samples were collected 32 times from both Euclid and Villa Angela beaches. The phycocyanin intergenic spacer (PC-IGS) and the microcystin-producing (mcyA) gene in M. aeruginosa were quantified with qPCR. PC-IGS and mcyA were detected in 50.0% and 39.1% of samples, respectively, and showed increased occurrences after mid-August. Correlation and regression analyses showed that water temperature was negatively correlated with M. aeruginosa markers and microcystin. The densities of mcyA and the g-Bfra were predicted by nitrate, implicating fecal contamination as contributing to the growth of M. aeruginosa by nitrate loading. Microcystin was correlated with mcyA (r = 0.413, p \u3c 0.01), suggesting toxin-producing M. aeruginosa populations may significantly contribute to microcystin production. Additionally, microcystin was correlated with total phosphorus (r = 0.628, p \u3c 0.001), which was higher at Euclid (p \u3c 0.05), possibly contributing to higher microcystin concentrations at Euclid
Where Are They Now? Where Are We Now?
In this paper we, a research team comprising one professor of education and four graduate students document our reflections on questions we have about the challenges of documenting the impact of teacher education coursework and on our collective research. This paper is organized into three, separate sections. In the first section we present data that Patricia collected while observing Renee teach the same group of prospective English students over two semesters. These courses, C&I 301 (Introduction to Teaching in a Diverse Society) and C&I 302 (Teaching Diverse Middle Grades Students), are the first two courses in a four course sequence that integrate methods of teaching English with critical analysis of schooling and with reflection on one’s own transition from student to teacher. For the two subsequent courses (C&I 303, Teaching Diverse High School Students; C&I 304, Assessing Secondary School Students) the students were taught by different instructors and, during C&I 304, were student teaching. The term, “diversity” is included in the course titles because the teacher education program emphasizes that multicultural education is not a separate course, but that celebrating and working productively with a diverse student population is embedded in everything we do as teachers of adolescents (and adults). In this paper we respond to two recommendations Renee and Patricia have raised in previous works (Clift & Brady, 2003; Clift, 2004) in that we are exploring the ways in which longitudinal study can be incorporated into self-study; we are also using friendly critics (Patricia, Raul, Jason, and Soo Joung) as we analyze Renée’s teaching and the potential impact of her courses (as well as that of the larger teacher education program) on thirteen teacher education graduates’ developing practice. (These graduates have all been out of the teacher education program for two years now.) As our work proceeded we realized that as a team we were grappling with issues of power, authority, and voice in both the selfstudy and larger study. We have shaped this paper to allow others to glimpse our process and the questions it continues to raise for our work
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Efficacy and safety of ginsam, a vinegar extract from Panax ginseng, in type 2 diabetic patients: Results of a double‐blind, placebo‐controlled study
Abstract Aims/Introduction: The efficacy, dose–response relationship and safety of ginsam, a vinegar extract from Panax ginseng, were evaluated in an 8‐week, double‐blind, randomized, placebo‐controlled study in drug‐naïve patients with type 2 diabetes. Materials and Methods: A total of 72 diabetic patients were randomized to receive 1500, 2000 or 3000 mg of ginsam, or placebo daily for 8 weeks (n = 18 in each group). The primary end‐point was the changes from the baseline HbA1c level. The secondary end‐points were the changes of fasting and postprandial 2‐h glucose concentration, and the proportion of patients achieving a reduction in HbA1c >0.5%. Results: In the intention‐to‐treat analysis, ginsam treatment reduced HbA1c level significantly: −0.56 ± 0.25% in the 1500 mg group, −0.31 ± 0.12% in the 2000 mg group, and −0.29 ± 0.11% in the 3000 mg group (all P 0.5% differed significantly between the placebo group (11.1%) and the 1500 mg (27.8%) and 2000 mg (27.8%) groups. No severe adverse events were observed in any group. Conclusions: An 8‐week treatment with ginsam, a vinegar extract from P. ginseng, moderately improved HbA1c level and was well tolerated in type 2 diabetic patients with inadequate glycemic control. This trial was registered with ClinicalTrial.Gov (no. NCT01008163). (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00185.x, 2011
Photodynamics Simulations of Thymine: Relaxation into the First Excited Singlet State
Ab initio nonadiabatic dynamics simulations are reported for thymine with focus on the S2 → S1deactivation using the state-averaged CASSCF method. Supporting calculations have been performed on vertical excitations, S1 and S2 minima, and minima on the crossing seam using the MS-CASPT2, RI-CC2, MR-CIS, and MR-CISD methods. The photodynamical process starts with a fast (\u3c100 fs) planar relaxation from the S2 ππ* state into the πOπ* minimum of the S2 state. The calculations demonstrate that two π-excited states (denoted ππ* and πOπ*) are actually involved in this stage. The time in reaching the S2/S1 intersections, through which thymine can deactivate to S1, is delayed by both the change in character between the states as well as the flatness of the S2 surface. This deactivation occurs in an average time of 2.6 ps at the lowest-energy region of the crossing seam. After that, thymine relaxes to the nπ* minimum of the S1state, where it remains until the transfer to the ground state takes place. The present dynamics simulations show that not only the πOπ* S2 trapping but also the trapping in the nπ* S1 minimum contribute to the elongation of the excited-state lifetime of thymine
Genome-Wide Association Analyses of Biological Responses to Heat Stress in Pigs
With genetic selection for rapid, lean tissue accretion, pigs are becoming increasingly sensitive to heat stress (HS) due to their physiological limitations such as the lack of functional sweat glands to effectively dissipate heat. Increased respiration rate and reduced feed intake are immediate and conserved biological responses to HS in pigs and other livestock species. Genetic differences in how animals respond to high ambient temperatures have been previously reported, but genetic factors contributing to the response variability remain ill-defined. In this study, porcine high density single nucleotide polymorphism (SNP) beadchips were used to genotype 236 female pigs who had been exposed to HS conditions, and analyzed to detect chromosomal regions associated with biological responses measured before and after HS, including rectal temperature, respiration rate, feed intake, and body weight loss. We identified significant gene region associations for rectal temperature on SSC12, respiration rate on SSC14 and SSC16, as well as feed efficiency and weight loss on SSC13. Further analyses of these detected regions will likely reveal potential candidate genes and suggest molecular mechanisms contributing to the variability in the biological response of pigs to environmentally-induced hyperthermia
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