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Powerful Way (powerful + way)
Selected AbstractsA Framework for Evaluating and Planning Assessments Intended to Improve Student AchievementEDUCATIONAL MEASUREMENT: ISSUES AND PRACTICE, Issue 3 2009Paul D. Nichols Assessments labeled as formative have been offered as a means to improve student achievement. But labels can be a powerful way to miscommunicate. For an assessment use to be appropriately labeled "formative," both empirical evidence and reasoned arguments must be offered to support the claim that improvements in student achievement can be linked to the use of assessment information. Our goal in this article is to support the construction of such an argument by offering a framework within which to consider evidence-based claims that assessment information can be used to improve student achievement. We describe this framework and then illustrate its use with an example of one-on-one tutoring. Finally, we explore the framework's implications for understanding when the use of assessment information is likely to improve student achievement and for advising test developers on how to develop assessments that are intended to offer information that can be used to improve student achievement. [source] Extracting long-term patterns of population changes from sporadic counts of migrant birdsENVIRONMETRICS, Issue 5 2010Joanna Mills Flemming Abstract Declines of many North American birds are of conservation concern. For almost 40 years, experienced birders have kept daily counts of migrant landbirds during visits to Seal and Brier Islands, both of which are off Nova Scotia's southern tip. Here we assess the utility of Generalized Additive Models (GAMs) to extract patterns of population change of a common migrant to Seal Island, the Ruby-crowned Kinglet, while controlling for other influences including season, weather and effort. We also demonstrate, using counts of the Kinglet from Brier Island as well as counts of another common migrant, the Yellow-rumped Warbler, how our GAM methods can combine data from different geographic areas or distinct species. Most existing analyses of similar long-term data sets have used linear models to estimate trends. Our results and comparisons suggest that GAMs are a powerful way of extracting more information from such data. Copyright © 2009 John Wiley & Sons, Ltd. [source] Gene expression silencing with ,specific' small interfering RNA goes beyond specificity , a study of key parameters to take into account in the onset of small interfering RNA off-target effectsFEBS JOURNAL, Issue 11 2008Sébastien Vankoningsloo RNA-mediated gene silencing (RNA interference) is a powerful way to knock down gene expression and has revolutionized the fields of cellular and molecular biology. Indeed, the transfection of cultured cells with small interfering RNAs (siRNAs) is currently considered to be the best and easiest approach to loss-of-function experiments. However, several recent studies underscore the off-target and potential cytotoxic effects of siRNAs, which can lead to the silencing of unintended mRNAs. In this study, we used a low-density microarray to assess gene expression modifications in response to five different siRNAs in various cell types and transfection conditions. We found major differences in off-target signature according to: (a) siRNA sequence; (b) cell type; (c) duration of transfection; and (d) post-transfection time before analysis. These results contribute to a better understanding of important parameters that could impact on siRNA side effects in knockdown experiments. [source] Atomic-Level Studies of Molecular Self-Assembly on Metallic SurfacesADVANCED MATERIALS, Issue 10-11 2009Giulia Tomba Abstract Shrinking devices to the nanoscale, while still maintaining accurate control on their structure and functionality is one of the major technological challenges of our era. The use of purposely directed self-assembly processes provides a smart alternative to the troublesome manipulation and positioning of nanometer-sized objects piece by piece. Here, we report on a series of recent works where the in-depth study of appropriately chosen model systems addresses the two key-points in self-assembly: building blocks selection and control of bonding. We focus in particular on hydrogen bonding because of the stability, precision and yet flexibility of nanostructures based on this interaction. Complementing experimental information with advanced atomistic modeling techniques based on quantum formalisms is a key feature of most investigations. We thus highlight the role of theoretical modeling while we follow the progression in the use of more and more complex molecular building blocks, or "tectons". In particular, we will see that the use of three-dimensional, flexible tectons promises to be a powerful way to achieve highly sophisticated functional nanostructures. However, the increasing complexity of the assembly units used makes it generally more difficult to control the supramolecular organization and predict the assembling mechanisms. This creates a case for developing novel analysis methods and ever more advanced modeling techniques. [source] Genetically Modified Animal Models as Tools for Studying Bone and Mineral Metabolism,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2004Rachel A Davey Abstract Genetic modification of mice is a powerful tool for the study of bone development and metabolism. This review discusses the advantages and disadvantages of various approaches used in bone-related research and the contributions these studies have made to bone biology. Genetic modification of mice is a powerful tool for the study of bone development and metabolism. This review discusses the advantages and disadvantages of various approaches used in bone-related research and the contributions these studies have made to bone biology. The approaches to genetic modification included in this review are (1) overexpression of genes, (2) global gene knockouts, (3) tissue-specific gene deletion, and (4) gene knock-in models. This review also highlights issues that should be considered when using genetically modified animal models, including the rigorous control of genetic background, use of appropriate control lines, and confirmation of tissue specificity of gene expression where appropriate. This technology provides a unique and powerful way to probe the function of genes and is already revolutionizing our approach to understanding the physiology of bone development and metabolism. [source] Drama activities as ideational resources for primary-grade children in urban science classroomsJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 3 2010Maria Varelas Abstract In this study we explored how dramatic enactments of scientific phenomena and concepts mediate children's learning of scientific meanings along material, social, and representational dimensions. These drama activities were part of two integrated science-literacy units, Matter and Forest, which we developed and implemented in six urban primary-school (grades 1st,3rd) classrooms. We examine and discuss the possibilities and challenges that arise as children and teachers engaged in scientific knowing through such experiences. We use Halliday's (1978. Language as social semiotic: The social interpretation of language and meaning. Baltimore, MD: University Park Press) three metafunctions of communicative activity,ideational, interpersonal, and textual,to map out the place of the multimodal drama genre in elementary urban school science classrooms of young children. As the children talked, moved, gestured, and positioned themselves in space, they constructed and shared meanings with their peers and their teachers as they enacted their roles. Through their bodies they negotiated ambiguity and re-articulated understandings, thus marking this embodied meaning making as a powerful way to engage with science. Furthermore, children's whole bodies became central, explicit tools used to accomplish the goal of representing this imaginary scientific world, as their teachers helped them differentiate it from the real world of the model they were enacting. Their bodies operated on multiple mediated levels: as material objects that moved through space, as social objects that negotiated classroom relationships and rules, and as metaphorical entities that stood for water molecules in different states of matter or for plants, animals, or non-living entities in a forest food web. Children simultaneously negotiated meanings across all of these levels, and in doing so, acted out improvisational drama as they thought and talked science. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47: 302,325, 2010 [source] Promoting complex systems learning through the use of conceptual representations in hypermediaJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 9 2009Lei Liu Abstract Studying complex systems is increasingly important in many science domains. Many features of complex systems make it difficult for students to develop deep understanding. Our previous research indicated that a function-centered conceptual representation is part of the disciplinary toolbox of biologists, suggesting that it is an appropriate representation to help students develop deep understanding. This article reports on the results of two experiments that investigate how hypermedia using a conceptual representation influences pre-service teachers' and middle school students' learning of a complex biological system, the human respiratory system. We designed two versions of instructional hypermedia based on the structure,behavior-function conceptual representation. One hypermedia was function-centered which emphasized the function and behavior of the system, whereas the other was focused on the structure of the system. We contrasted the instructional effectiveness of these two alternative conceptual representations. The results of both studies indicated that participants using the function-centered hypermedia developed deeper understanding than those using the structure-centered version. This proof-of-concept study suggests that the function-centered conceptual representation is a powerful way to promote complex systems understanding. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 1023,1040, 2009 [source] Click Chemistry-Led Advances in High Content Functional ProteomicsMOLECULAR INFORMATICS, Issue 11-12 2007Abstract The availability of complete genome sequences for numerous eukaryotic and prokaryotic organisms has inspired the advent of new methods to functionally characterize proteins on a global scale. Chemical approaches, in particular, have emerged as a powerful way to investigate the proteome, providing small-molecule probes that report on protein activity and Post-Translational Modification (PTM) state directly in complex biological samples. Many of the key advances made in chemical proteomics can be attributed to the development of efficient bio-orthogonal reactions such as the copper (I)-catalyzed Huisgen's azide,alkyne cycloaddition, a reaction commonly known as "Click Chemistry" (CC). The generation of "clickable" proteomics probes has removed the requirement for bulky reporter tags, thereby allowing access to more biologically relevant systems such as live cells or animals. The versatility of CC has also allowed for greater experimental efficiency, as different reporter tags (i.e., a fluorophore for detection or biotin for enrichment) can be appended to a single probe. Such advances have enabled researchers to identify protein activities dysregulated in disease states, assess the selectivity of enzyme inhibitors in vivo, and inventory specific PTMs on a proteome-wide scale. [source] The temperature of the intergalactic medium and the Compton y parameterMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2004Pengjie Zhang ABSTRACT The thermal Sunyaev,Zeldovich (SZ) effect directly probes the thermal energy of the Universe. Its precision modelling and future high-accuracy measurements will provide a powerful way to constrain the thermal history of the Universe. In this paper, we focus on the precision modelling of the gas density weighted temperature and the mean SZ Compton y parameter. We run high-resolution adiabatic hydrodynamic simulations adopting the WMAP cosmology to study the temperature and density distribution of the intergalactic medium (IGM). To quantify possible simulation limitations, we run n=,1, , 2 self-similar simulations. Our analytical model on is based on energy conservation and matter clustering and has no free parameter. Combining both simulations and analytical models thus provides the precision modelling of and . We find that the simulated temperature probability distribution function and shows good convergence. For the WMAP cosmology, our highest-resolution simulation (10243 cells, 100 Mpc h,1 box size) reliably simulates with better than 10 per cent accuracy for z, 0.5. Toward z= 0, the simulation mass-resolution effect becomes stronger and causes the simulated to be slightly underestimated (at z= 0, ,20 per cent underestimated). Since is mainly contributed by the IGM at z, 0.5, this simulation effect on is no larger than ,10 per cent. Furthermore, our analytical model is capable of correcting this artefact. It passes all tests of self-similar simulations and WMAP simulations and is able to predict and to several per cent accuracy. For a low matter density ,CDM cosmology, the present is 0.32 (,8/0.84)(,m/0.268) keV, which accounts for 10,8 of the critical cosmological density and 0.024 per cent of the cosmic microwave background (CMB) energy. The mean y parameter is 2.6 × 10,6 (,8/0.84)(,m/0.268). The current upper limit of y < 1.5 × 10,5 measured by FIRAS has already ruled out combinations of high ,8, 1.1 and high ,m, 0.5. [source] Rational approaches to the neurobiologic study of youth at risk for bipolar disorder and suicideBIPOLAR DISORDERS, Issue 5p2 2006M Elizabeth Sublette Objectives:, The aims of this paper are to provide an overview of neuroimaging findings specific to bipolar disorder and suicide, and to consider rational approaches to the design of future in vivo studies in youth at risk. Methods:, Neuroimaging and related neurobiological literature pertaining to bipolar disorder and suicide in adult and pediatric samples was reviewed in a non-quantitative manner. Results:, Specific structural and functional brain findings in bipolar disorder are described, where possible in the context of relevant current neurobiological theories of etiology. Diagnostic and prognostic implications are discussed. Conclusions:, The simultaneous use of complementary neurobiological approaches may be a powerful way of identifying and validating factors reliably associated with bipolar disorder and suicide. A profile of neurobiological markers with which to screen for bipolar disorder and suicide risk may provide for earlier and more accurate diagnosis, perhaps even in the pre- or subsyndromal stages in high-risk youth. [source] Phylogenetic algorithms and the evolution of species communities in forest fragmentsCLADISTICS, Issue 1 2005Roseli Pellens In forest fragmentation studies, low specific richness in small fragments and community nestedness are usually considered to result from species loss. However, except in the case of fragmentation experiments, these studies cannot distinguish between original low richness and secondary species loss, or between original high richness and secondary colonizations in fragments. To distinguish between these possibilities is a matter of historical inference for which phylogenetic algorithms are designed. The methods of phylogenetic analysis, and especially parsimony analysis, can be used to find a tree of relationships between communities from different forest fragments, taking the presence or absence of species among different communities as characters. Parsimony analysis searches if species subsets can be classified in a nested hierarchy, and also establishes how the communities evolved, polarizing species changes into either extinctions or colonizations. By re-analyzing two classical studies in this new and powerful way, we demonstrate that the differences between fragments and large continuous forests cannot be attributed to species loss in all cases, contrary to expectations from models. © The Willi Hennig Society 2005. [source] | ||||||||||||||||