4,326 research outputs found
Electrophysiological Correlates of Reading Processes in School Age Children
Orthographic and phonological decoding skills are known to be important for learning to read. In an attempt to develop physiologically based screening tools which may identify children at risk for developing these skills, Auditory Event Related Potentials (ERP) were recorded from 84 nine-year-olds to a series of Probe tones while they were engaged in a series of orthographic, phonological, and spelling tasks. Electrodes were applied over both hemispheres at the frontal, temporal, and parietal regions of the scalp. Analyses focus on the relationship between hemisphere differences and children\u27s performance on each of these tasks
Segmental migration of trunk neural crest: time-lapse analysis reveals a role for PNA-binding molecules
Trunk neural crest cells migrate through the somites in a striking segmental fashion, entering the rostral but not caudal sclerotome, via cues intrinsic to the somites. Attempts to define the molecular bases of these cues have been hampered by the lack of an accessible assay system. To examine trunk neural crest migration over time and to perturb candidate guiding molecules, we have developed a novel explant preparation. Here, we demonstrate that trunk regions of the chicken embryo, placed in explant culture, continue to develop apparently normally for 2 days. Neural crest cells, recognized by prelabeling with DiI or by poststaining with the HNK-1 antibody, migrate in the somites of the explants in their typical segmental pattern. Furthermore, this paradigm allows us to follow trunk neural crest migration in situ for the first time using low-light-level videomicroscopy. The trajectories of individual neural crest cells were often complex, with cells migrating in an episodic mode encompassing forward, backward and lateral movements. Frequently, neural crest cells migrated in close-knit groups of 2–4 cells, moving at mean rates of migration of 10–14 µm/hour. Treatment of the explants with the lectin peanut agglutinin (PNA) both slowed the rate and altered the pattern of neural crest migration. Neural crest cells entered both the rostral and caudal halves of the sclerotome with mean rates of migration ranging from 6 to 13 µm/hour. These results suggest that peanut agglutinin-binding molecules are required for the segmental patterning of trunk neural crest migration. Because this approach permits neural crest migration to be both observed and perturbed, it offers the promise of more direct assays of the factors that influence neural crest development
Identifying a sufficient core group for trachoma transmission.
BackgroundIn many infectious diseases, a core group of individuals plays a disproportionate role in transmission. If these individuals were effectively prevented from transmitting infection, for example with a perfect vaccine, then the disease would disappear in the remainder of the community. No vaccine has yet proven effective against the ocular strains of chlamydia that cause trachoma. However, repeated treatment with oral azithromycin may be able to prevent individuals from effectively transmitting trachoma.Methodology/principal findingsHere we assess several methods for identifying a core group for trachoma, assuming varying degrees of knowledge about the transmission process. We determine the minimal core group from a completely specified model, fitted to results from a large Ethiopian trial. We compare this benchmark to a core group that could actually be identified from information available to trachoma programs. For example, determined from the rate of return of infection in a community after mass treatments, or from the equilibrium prevalence of infection.Conclusions/significanceSufficient groups are relatively easy for programs to identify, but will likely be larger than the theoretical minimum
Virtual Laboratory Enabling Collaborative Research in Applied Vehicle Technologies
The virtual laboratory is a new technology, based on the internet, that has had wide usage in a variety of technical fields because of its inherent ability to allow many users to participate simultaneously in instruction (education) or in the collaborative study of a common problem (real-world application). The leadership in the Applied Vehicle Technology panel has encouraged the utilization of this technology in its task groups for some time and its parent organization, the Research and Technology Agency, has done the same for its own administrative use. This paper outlines the application of the virtual laboratory to those fields important to applied vehicle technologies, gives the status of the effort, and identifies the benefit it can have on collaborative research. The latter is done, in part, through a specific example, i.e. the experience of one task group
Positive and Negative Symptoms of Schizotypy and the Five-Factor Model: A Domain and Facet Level Analysis
In this study, we investigated the Five-factor model in the concurrent prediction of positive symptomschizotypy as measured by the Magical Ideation (Eckblad & Chapman, 1983) and Perceptual Aberration (Chapman, Chapman, & Raulin, 1978) scales and negative symptom schizotypy as measured by the Physical Anhedonia (Chapman, Chapman, & Raulin, 1976) and Revised Social Anhedonia (Eckblad, Chapman, Chapman, & Mishlove, 1982; Mishlove & Chapman, 1985) scales. Previous studies suggest that these measures reflect the core symptoms found in schizotypal and schizoid personality disorder (Bailey, West, Widiger, & Freiman, 1993). Negative symptoms were significantly predicted by Neuroticism (+), Extraversion (-), Openness (-), and Agreeableness (-) domains of the Revised NEO Personality Inventory (NEO-PI-R; Costa & McCrae, 1992). Additionally, positive symptoms were significantly predicted by Neuroticism (+), Openness (+), and Agreeableness (-). In addition, we examined the validity of lower order traits in describing these symptoms of character pathology. These findings lend further support for the use of domain and facet scales of the NEO-PI-R in the identification of personality pathology
Psychopathy and the Five Factor Model in a Noninstitutionalized Sample: A Domain and Facet Level Analysis
The current study examined the relationship of the Five Factor Model (FFM) of personality to primary and secondary psychopathic dispositions in a noninstitutionalized sample. Previous investigations suggest that Agreeableness, Conscientiousness, and Neuroticism are basic personality traits that characterize psychopathy. However, few studies have examined the relationship of the FFM to primary and secondary psychopathic attributes, respectively. In the current study, the relationship of the FFM using the NEO-PI-R to primary and secondary psychopathic dispositions was investigated in a sample of young adults. Previous findings were extended by (1) addressing the relationship of higher and lower order FFM traits (i.e., facet scales) to primary and secondary psychopathy in a subclinical sample and (2) examining sex differences in FFM traits in relation to these two psychopathic dispositions. Although a number of differences were found between men and women for the FFM in terms of primary psychopathy, few sex differences were noted with respect to secondary psychopathy. In addition, examination of facet scale relationships to primary and secondary psychopathy further clarify the role of the FFM in psychopathy. These findings lend further support to the use of domain and facet scales of the NEO-PI-R in the identification of personality pathology in noninstitutionalized populations
Working Partnerships, Partnerships Working
Involvement in community partnerships at Virginia Commonwealth University has its roots in the institution\u27s history. The Medical College of Virginia, founded in1838, and the Richmond Professional Institute, founded in 1917, both sought to extend knowledge into the community to change peoples\u27 lives for the better. Today, the VCU campuses are even more entwined with the City of Richmond -- physically, and increasingly so as a partner in the economic and social challenges and opportunities facing the City
Public perceptions of drinking water: A postal survey of residents with private water supplies
Background: In Canada, the legal responsibility for the condition of private water supplies,
including private wells and cisterns, rests with their owners. However, there are reports that
Canadians test these water supplies intermittently and that treatment of such water is uncommon.
An estimated 45% of all waterborne outbreaks in Canada involve non-municipal systems. An
understanding of the perceptions and needs of Canadians served by private water supplies is
essential, as it would enable public health professionals to better target public education and
drinking water policy. The purpose of this study was to investigate the public perceptions of private
water supplies in the City of Hamilton, Ontario (Canada), with the intent of informing public
education and outreach strategies within the population.
Methods: A cross-sectional postal survey of 246 residences with private water supplies was
conducted in May 2004. Questions pertained to the perceptions of water quality and alternative
water sources, water testing behaviours and the self-identified need for further information.
Results: Private wells, cisterns or both, were the source of household water for 71%, 16% and
13% of respondents, respectively. Although respondents rated their water quality highly, 80% also
had concerns with its safety. The most common concerns pertained to bacterial and chemical
contamination of their water supply and its potential negative effect on health. Approximately 56%
and 61% of respondents used in-home treatment devices and bottled water within their homes,
respectively, mainly due to perceived improvements in the safety and aesthetic qualities compared
to regular tap water. Testing of private water supplies was performed infrequently: 8% of
respondents tested at a frequency that meets current provincial guidelines. Two-thirds of
respondents wanted more information on various topics related to private water supplies. Flyers
and newspapers were the two media reported most likely to be used.
Conclusion: Although respondents rated their water quality highly, the majority had concerns
regarding the water from their private supply, and the use of bottled water and water treatment
devices was extensive. The results of this study suggest important lines of inquiry and provide
support and input for public education programs, particularly those related to private water testing,
in this population
Slithering Into Summer: Ideas for introducing your students to herpetology.
The article discusses how elementary school students can learn about herpetology during the summer through educational programs. Activities included studying cover boards, aquatic turtle traps and vernal pools. The author provides factors for teachers to consider when exploring summer programs, such as program structure, safety and student interest
The Network Turn
This Element contends that networks are a category of study that cuts across traditional academic barriers, uniting diverse disciplines through a shared understanding of complexity in our world. This title is also available as Open Access on Cambridge Core
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