6,228 research outputs found
COMMUNITY GARDENS AND ECOLOGICAL CITIZENSHIP: THEIR POTENTIAL AND LIMITATIONS IN FOSTERING ENVIRONMENTALISM
Mainstream agricultural and food production methods are a major source of environmental degradation, which has not been addressed by large-scale and global initiatives. Alternatively, grassroots and local initiatives may be more effective at alleviating the causes of environmental degradation associated with food and agriculture. Specifically, community gardens are an important local greenspace that can be used to address and educate individuals about the importance of food and the environment. However, certain barriers need to be overcome and addressed before community gardens are successfully implement. The participation and interaction at community gardens may provide a pathway to long-term commitment to sustainability, pushing individuals to adopt more environmentally supportive behaviors and a deeper commitment to environmentalism. Furthermore, community gardens can be used to improve current mainstream environmental educational practices that are often counterproductive. This paper also discusses potential future directions for research on community gardens
Effects of Content Acquisition Podcasts on Vocabulary Performance of Secondary Students With and Without Learning Disabilities
The purpose of this experimental research study was to investigate effects of using Content Acquisition Podcasts (CAPs) to provide vocabulary instruction to adolescents with and without learning disabilities (LD). A total of 279 urban high school students, including 30 with LD in an area related to reading, were randomly assigned to one of four experimental conditions with instruction occurring at individual computer terminals over a three-week period. The four experimental conditions contained various combinations of multimedia-instruction and evidence-based practices for vocabulary instruction including: (a) CAPs designed using validated instructional design principles and a combination of explicit instruction and the keyword mnemonic strategy (Group 1); (b) CAPs with validated design principles and only explicit instruction (Group 2); (c) CAPs with validated design principles and only the keyword mnemonic strategy (Group 3); and (d) multimedia instruction without adherence to validated design principles and explicit instruction (Group 4). Results indicated that students with LD who received vocabulary instruction using CAPs with explicit instruction and the keyword mnemonic strategy (Group 1) significantly outperformed all other students with LD on measures of vocabulary knowledge on a posttest of 30 history-specific vocabulary terms, and again on a maintenance probe three weeks later for 10 history terms. In addition, students with LD in Group 1 significantly outperformed students without disabilities who received multimedia instruction that did not adhere to validated design principles at posttest and maintenance (Group 4), and had higher mean scores than students without LD in Groups 2 and 3. Students without disabilities in Group 1 significantly outperformed all other students at both posttest and maintenance. A student satisfaction survey indicated a strong student preference for learning vocabulary using the CAPs
Intact Bilateral Resting-State Networks in the Absence of the Corpus Callosum
Temporal correlations between different brain regions in the resting-state BOLD signal are thought to reflect intrinsic functional brain connectivity (Biswal et al., 1995; Greicius et al., 2003; Fox et al., 2007). The functional networks identified are typically bilaterally distributed across the cerebral hemispheres, show similarity to known white matter connections (Greicius et al., 2009), and are seen even in anesthetized monkeys (Vincent et al., 2007). Yet it remains unclear how they arise. Here we tested two distinct possibilities: (1) functional networks arise largely from structural connectivity constraints, and generally require direct interactions between functionally coupled regions mediated by white-matter tracts; and (2) functional networks emerge flexibly with the development of normal cognition and behavior and can be realized in multiple structural architectures. We conducted resting-state fMRI in eight adult humans with complete agenesis of the corpus callosum (AgCC) and normal intelligence, and compared their data to those from eight healthy matched controls. We performed three main analyses: anatomical region-of-interest-based correlations to test homotopic functional connectivity, independent component analysis (ICA) to reveal functional networks with a data-driven approach, and ICA-based interhemispheric correlation analysis. Both groups showed equivalently strong homotopic BOLD correlation. Surprisingly, almost all of the group-level independent components identified in controls were observed in AgCC and were predominantly bilaterally symmetric. The results argue that a normal complement of resting-state networks and intact functional coupling between the hemispheres can emerge in the absence of the corpus callosum, favoring the second over the first possibility listed above
Numerical analysis of four-wave mixing between 2 ps mode-locked laser pulses in a tensile-strained bulk SOA
A numerical model of four-wave mixing between 2-ps pulses in a tensile-strained bulk semiconductor optical amplifier is presented. The model utilizes a modified Schrodinger equation to model the pulse propagation. The Schrodinger equation parameters such as the material gain first and second order dispersion, linewidth enhancement factors and optical loss coefficient are obtained using a previously developed steady-state model. The predicted four-wave mixing pulse characteristics show reasonably good agreement with experimental pulse characteristics obtained using frequency resolved optical gating
Influence of condimental stock foods on the digestibility of a corn ration fed to swine.
Every stock food manufacturer claims that his particular brand of food will give greater gains or cheaper gains when fed in addition to a ration than that ration will give when fed alone. This claim is based upon the assumption that the spices, seeds, barks, roots, and herbs of which each food is said to be “scientifically compounded,” either directly stimulate the glands of the stomach and intestines which have to do the work of digesting and assimilating the ration; or else that the compounds act indirectly on these glands by toning up the entire animal system, purifying the blood, etc.
Development of a novel Periconceptual Nutrition Score (PENS) to examine the relationship between maternal dietary quality and fetal growth
Background Maternal nutrition may influence intrauterine fetal development. To date, the relationship between contemporary European dietary guidelines and fetal growth has not been examined.
Aims To develop a novel Periconceptual Nutrition Score (PENS) to assess maternal dietary quality in early pregnancy and examine its relationship with fetal growth.
Study design Women were recruited conveniently at their first clinic visit and completed a supervised four day retrospective diet history. The PENS was developed using European Food Safety Authority recommended dietary intakes for pregnancy. The relationship between PENS and fetal growth was examined.
Subjects Women with a singleton pregnancy.
Outcome measures Birthweight, small for gestational age (SGA), neonatal head circumference.
Results and conclusions Of the 202 women, the mean age was 32.2 ± 5.0 years and 44.6% were nulliparas. The mean PENS was 9.4 ± 3.1. On multivariable regression, there was a positive relationship between the PENS and birthweight (beta = 45.3, 95%CI 14.8–75.9, P = 0.002) and neonatal head circumference (beta = 0.12, 95%CI 0.01–0.23, P = 0.03). Compared with the lowest PENS quartile, the mean birthweight was increased in the highest quartile (Mean difference 328 g, P = 0.02). The incidence of SGA was 16.4% (n = 10/61) in the lowest PENS quartile compared to 6.5% (n = 9/139) in the top three quartiles (P = 0.03). Thus, higher maternal dietary quality was associated with increased intrauterine fetal growth. The PENS is potentially useful in identifying those women before or during pregnancy who may benefit from dietary interventions that may optimise fetal growth. It may also be useful in tracking maternal dietary quality during pregnancy
Chemical and Mechanical Differences between Historic and Modern Scots Pine Wood
Timber is one of the most common historic building materials, but relatively little is known about how it ages in situ. Here we investigate historic and modern Scots pine to determine any chemical or mechanical differences between them. Fourier-transform infrared (FTIR) microscopy was used to investigate differences in the chemical composition of Scots pine (Pinus sylvestris L.) timber, comparing small samples from historic beams about 500 years old with modern timber. The hemicellulosic acetyl content was reduced by about half in the historic samples, uniformly across the thickness of the beams. A chemical mechanism was therefore suggested for the loss of acetyl groups, as has been observed in paper. In paper, deacetylation and the resulting release of acetic acid are accompanied by loss of strength. Mechanical testing of the historic timber was difficult because the available length of the samples along the grain was only 20 mm. After developing a miniaturized compression test developed for the purpose, it was shown that the relative stiffness of the historic Scots pine samples was reduced by about half compared to modern material
Empirical validation of the S-Score algorithm in the analysis of gene expression data
BACKGROUND: Current methods of analyzing Affymetrix GeneChip(® )microarray data require the estimation of probe set expression summaries, followed by application of statistical tests to determine which genes are differentially expressed. The S-Score algorithm described by Zhang and colleagues is an alternative method that allows tests of hypotheses directly from probe level data. It is based on an error model in which the detected signal is proportional to the probe pair signal for highly expressed genes, but approaches a background level (rather than 0) for genes with low levels of expression. This model is used to calculate relative change in probe pair intensities that converts probe signals into multiple measurements with equalized errors, which are summed over a probe set to form the S-Score. Assuming no expression differences between chips, the S-Score follows a standard normal distribution, allowing direct tests of hypotheses to be made. Using spike-in and dilution datasets, we validated the S-Score method against comparisons of gene expression utilizing the more recently developed methods RMA, dChip, and MAS5. RESULTS: The S-score showed excellent sensitivity and specificity in detecting low-level gene expression changes. Rank ordering of S-Score values more accurately reflected known fold-change values compared to other algorithms. CONCLUSION: The S-score method, utilizing probe level data directly, offers significant advantages over comparisons using only probe set expression summaries
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