2,277 research outputs found

    Graviton Production in Relativistic Heavy-Ion Collisions

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    We study the feasibility of producing the graviton of the novel Kaluza-Klein theory in which there are d large compact dimensions in addition to the 4 dimensions of Minkowski spacetime. We calculate the cross section for producing such a graviton in nucleus-nucleus collisions via t-channel photon-photon fusion using the semiclassical Weizsacker-Williams method and show that it can exceed the cross section for graviton production in electron-positron scattering by several orders of magnitude.Comment: 10 pages, 3 figures, accepted for publication in Physical Review

    Mutations in Drosophila enabled and rescue by human vasodilator-stimulated phosphoprotein (VASP) indicate important functional roles for Ena/VASP homology domain 1 (EVH1) and EVH2 domains

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    Journal ArticleDrosophila Enabled (Ena) was initially identified as a dominant genetic suppressor of mutations in the Abelson tyrosine kinase and, more recently, as a member of the Ena/human vasodilator-stimulated phosphoprotein (VASP) family of proteins. We have used genetic, biochemical, and cell biological approaches to demonstrate the functional relationship between Ena and human VASP

    Is The Late Neandertal Mandibular Sample from Vindija Cave (Croatia) Biased?

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    The late Neandertal sample from Vindija (Croatia) has been described as transitional between the earlier Central European Neandertals from Krapina (Croatia) and modern humans. However, the morphological differences indicating this transition may rather be the result of different sex and/or age compositions between the samples. This study tests the hypothesis that the metric differences between the Krapina and Vindija mandibular samples are due to sample bias. Mandibles are the focus of this paper because past studies have posited this region as particularly indicative of the Vindija sampleā€™s transitional nature. The results indicate that the metric differences between the Krapina and Vindija mandibular samples are not due to sample bias. This conclusion is consistent with an earlier analysis of sample bias for the Vindija supraorbital sample

    Student Awareness and Use of Rubrics in Online Classes

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    The design, development and deployment of online instruction has become standard practice. The focus of the study was on student perceptions of course rubrics and not on the rubrics, themselves, or the instructors. In order to improve student engagement online we conducted an exploratory study of the awareness and perceptions of course rubrics. Fifty graduate students completed an online survey at the end of the semester about their awareness and perceptions of course rubrics. All students reported that they were aware that course rubrics existed. They indicated that they had learned about this information through the course syllabus, professor announcements via email and posts to LMS. Most students reported reviewing rubrics prior to submitting an assignment. One of the key findings from this study was that students see rubrics as a mechanism for scaffolding their performance, and thus, instructors need to focus more effort on designing rubrics to accomplish more than student assessment

    Teaching & Learning The Spanish Aspect Using Blogs and Wikis: An Exploratory Study

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    This study investigated the influence of asynchronous computer text based technologies on the studentsā€™ performance when learning the preterite and the imperfect aspects in Spanish. Two research questions guided the study: Research Question 1) Is there a difference in studentsā€™ achievement levels in Spanish preterite and imperfect between those using wiki technologies and those using blog technologies after controlling for pre-intervention achievement levels? and Research Question 2) Are there differences in satisfaction levels for students learning Spanish preterite and imperfect via blog technologies as compared to those learning via wiki technologies? Results indicate that there were not significant differences between students who use blog or wiki technologies on performance levels when controlling for pre-existing knowledge. Results also indicated that there were not significant differences in satisfaction levels between those students using a wiki and those using a blog. These results suggest that wikis and blogs are good potential tools that may facilitate the teaching and learning of problematic grammar structures in a narrative context

    Do Prosecutors Use Interview Instructions or Build Rapport with Child Witnesses?

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    This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/bsl.2183This study examined the quality of interview instructions and rapport-building provided by prosecutors to 168 children aged 5-12 years testifying in child sexual abuse cases, preceding explicit questions about abuse allegations. Prosecutors failed to effectively administer key interview instructions, build rapport, or rely on open-ended narrative producing prompts during this early stage of questioning. Moreover, prosecutors often directed children's attention to the defendant early in the testimony. The productivity of different types of wh- questions varied, with what/how questions focusing on actions being particularly productive. The lack of instructions, poor quality rapport-building, and closed-ended questioning suggest that children may not be adequately prepared during trial to provide lengthy and reliable reports to their full ability.This research was supported by NICHD Grant HD047290 to Dr. Thomas Lyon

    Bronze and Iron Age Finds from Romualdā€™s Cave, ronze and Iron Age Finds from Romualdā€™s Cave, Istria: 2014 Excavation Season

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    Archaeological excavations in Romualdā€™s Cave (Lim Channel, Istria, Croatia) have yielded evidence of human activity stretching back to the Middle Palaeolithic. This paper reports on recent Bronze Age/Early Iron Age discoveries uncovered during excavations as part of the Croatian National Science Foundation funded project: ā€œArchaeological Investigations into the Late Pleistocene and Early Holocene of the Lim Channel, Istria.ā€ Fragmentary skeletal remains from at least two individuals were excavated, and a direct radiocarbon date from one of the remains is commensurate with a Bronze Age attribution. The recovered ceramics confirm this age attribution, although they range from the Middle Bronze Age to incipient Iron Age in character. Furthermore, the ceramics indicate that the human activities in Romualdā€™s Cave were associated with the nearby settlements of Gradina and St. Martin

    Microbiology and atmospheric processes: Biological, physical and chemical characterization of aerosol particles

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    The interest in bioaerosols has traditionally been linked to health hazards for humans, animals and plants. However, several components of bioaerosols exhibit physical properties of great significance for cloud processes, such as ice nucleation and cloud condensation. To gain a better understanding of their influence on climate, it is therefore important to determine the composition, concentration, seasonal fluctuation, regional diversity and evolution of bioaerosols. In this paper, we will review briefly the existing techniques for detection, quantification, physical and chemical analysis of biological particles, attempting to bridge physical, chemical and biological methods for analysis of biological particles and integrate them with aerosol sampling techniques. We will also explore some emerging spectroscopy techniques for bulk and single-particle analysis that have potential for in-situ physical and chemical analysis. Lastly, we will outline open questions and further desired capabilities (e. g., in-situ, sensitive, both broad and selective, on-line, time-resolved, rapid, versatile, cost-effective techniques) required prior to comprehensive understanding of chemical and physical characterization of bioaerosols
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