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"Modeling Mathematical Ideas" combining current research and practical strategies to build teachers and students strategic competence in problem solving.This must-have book supports teachers in understanding learning progressions that addresses conceptual guiding posts as well as students' common misconceptions in investigating and discussing important mathematical ideas related to number sense, computational fluency, algebraic thinking and proportional reasoning. In each chapter, the authors opens with a rich real-world mathematical problem and presents classroom strategies (such as visible thinking strategies & technology integration) and other related problems to develop students' strategic competence in modeling mathematical ideas.

DNA-mediated gene transfer techniques have revolutionalized molecular biology and are used extensively to study the function and regulation of eukaryotic genes in a variety of cell types. In general, expression of genes in mammalian cells can be studied by either stable transformation or by transient expression. Stable transformation of cells expressing the gene of interest can be achieved by cotransfection of the gene cloned in an appropriate expression vector under the control of a constitutive or inducible eukaryotic cellular or viral promoter and a vector that carries a dominant selectable marker such as Eco-gpt (1) or neo (2). Since the DNA-mediated gene transfer methods target only a fraction of cells for gene expression, the isolation of stably transfected cells with a selectable marker gives rise to a cell population expressing the gene of interest free of untransfected cells under conditions of drug selection. However, this method of selection is a long-term process and may have adverse effects on host cell functions such as cell growth or chromosomal rearrangements due to integration of a single or multiple copies of the selectable marker gene. Transient expression without a dominant selectable marker allows functional analysis of the transfected gene within 24-72 h after transfection but suffers from the drawback that the presence of a large fraction of untransfected cells in the milieu of cells expressing the gene of interest may give rise to problems of interference due to high background. Therefore, it was necessary to develop a method for isolation of transiently transfected cells free of untransfected cells within 24-72 h after transfection. With this overall goal in mind, the previously developed "panning" methodology was modified to isolate transiently transfected cells expressing the gene of interest together with a cotransfected cell surface marker gene using the magnetic affinity cell sorting (MACS) technology (3; for reviews, see refs 4-8). The MACS methodology allows the separation of cells expressing a surface protein away from those lacking the marker. The cell surface marker could be either introduced into cells by DNA-mediated gene transfer techniques or be an endogenously-expressing protein on the surface of selective cell type. In either case, the antibodies against the surface protein attached to a magnetic matrix are used to selectively "pull out" cells expressing that surface marker with the application of a magnetic field under appropriate experimental conditions whereas the cells lacking the marker remain unaffected. Expression of any cell surface protein for which a suitable antibody is available in a variety of cell types using DNA-mediated gene transfer methods allows this methodology to be useful in a wide range of biological applications (6,8,9). In the initial stages of development of this application of MACS methodology to transfected cells, readily assayable reporter gene product such as chloramphenicol acetyltransferase (CAT) was used as the gene of interest in conjunction with the cell surface markers such as the vesicular stomatitis virus glycoprotein (VSV-G) and the Tat subunit of interleukin 2 receptor (IL-2R) for transient expression in mammalian cells by DNA-mediated transfection techniques (3,10,11). Subsequently, it was shown that MACS could be successfully used to select a rare population of cells expressing the P-glycoprotein, the product of multiple drug resistant (mdr) gene (6,8,9) among human lymphomas as well as for selection of virus-infected cells expressing a surface protein (using dengue virus as an example) (6). The experimental conditions for MACS methodology have undergone some improvement over the original protocol published (3), and the modified procedure is described in this chapter. [ABSTRACT FROM AUTHOR]

At least 28 animal models provide insight into the etiological and pathophysiological basis of polycystic ovary syndrome (PCOS). About 50% of them, however, either do not show sufficient traits meriting designation of a PCOS phenotype or exhibit alternate features mimicking other disorders, such as hyperprolactinemia. In contrast, animal models of fetal programming through androgen excess show remarkable resilience and reliability in replicating PCOS, including metabolic defects in males, and therefore strongly implicate a fetal etiology in the developmental origins of PCOS. This chapter reviews the relevance of animal models for PCOS and their potential value for providing insight into the etiology and pathophysiology of this disorder. [ABSTRACT FROM AUTHOR]

As discussed in the previous chapter, offline analysis can be used to generate a schedule of DVFS state changes to minimize energy consumption, while ensuring sufficient processing cycles are available for all tasks to meet their deadlines, even under worst-case computation requirements. However, invocations of real-time tasks typically use less than their specified worst-case computation requirements, presenting an opportunity for further energy conservation. This chapter outlines three online, dynamic techniques to more aggressively scale back processing frequency and voltage to conserve energy when task computation cycles vary, yet continue to provide timeliness guarantees for worst-case execution time scenarios. [ABSTRACT FROM AUTHOR]

Inactivation of the retinoblastoma tumor suppressor protein, Rb, is necessary for the normal progression of the mammalian cell cycle.[1] Studies over the past fifteen years have shown that Rb protein is inactivated by kinases associated with cyclins, especially cyclins D and E, which facilitate the entry of cells from the G1 to S phase.[1]–[3] Though the cyclin/cdk mediated inactivation of Rb has been well studied, the role of other kinases in regulating Rb function is relatively less understood.[4] It has been shown that components of the MAP kinase cascade, including ERK kinases as well as the Raf-1 kinase can phosphorylate Rb efficiently in response to proliferative signals.[5],[6] A physiological role for Raf-1 in inactivating Rb during cell cycle progression has been established.[7] These kinases seem to work in conjunction with the cyclin-cdks, facilitating phosphorylation by the latter; at the same time, over-expression of Raf-1 could inactivate Rb as efficiently as cyclin-cdks. [6],[7] Similarly, it has been shown that Rb is inactivated upon apoptotic signaling as well.[8]–[10] Such inactivation events appear to be mediated by the p38 kinase in a human T-cell leukemia system as well as a neuronal system.[11],[12] The inactivation of Rb upon apoptotic signaling seems to be totally independent of cyclins and cdks and occurring on different sites on the Rb protein.[13] In addition to the p38 kinase, the stress-induced kinase JNK1 has been shown to affect Rb and E2F functions in certain apoptotic situations.[11],[14] Recently, the apoptosis signal regulating kinase, ASK1, was found to interact with Rb and overcome its anti-apoptotic activities.[15] These studies suggest that while cyclin dependent kinases are the predominant regulators of Rb, especially during cell cycle progression, other kinases are capable of functionally inactivating Rb in response to multiple stimuli. Since inactivation of the Rb protein is widespread in a wide array of human tumors,[10],[16],[17] understanding the mechanisms that inactivate Rb in response to normal physiological stimuli would be valuable in developing novel therapeutic strategies to combat cancer. [ABSTRACT FROM AUTHOR]

Text detection and tracking is an important step in a video content analysis system as it brings important semantic clues which is a vital supplemental source of index information. While there has been a significant amount of research done on video text detection and tracking, there are very few works on performance evaluation of such systems. Evaluations of this nature have not been attempted because of the extensive effort required to establish a reliable ground truth even for a moderate video dataset. However, such ventures are gaining importance now. In this paper, we propose a generic method for evaluation of object detection and tracking systems in video domains where ground truth objects can be bounded by simple geometric shapes (polygons, ellipses). Two comprehensive measures, one each for detection and tracking, are proposed and substantiated to capture different aspects of the task in a single score. We choose text detection and tracking tasks to show the effectiveness of our evaluation framework. Results are presented from evaluations of existing algorithms using real world data and the metrics are shown to be effective in measuring the total accuracy of these detection and tracking algorithms. [ABSTRACT FROM AUTHOR]

In [15,19] we showed how to combine propositional multimodal logics using Gabbay's fibring methodology. In this paper we extend the above mentioned works by providing a tableau-based proof technique for the combined/ fibred logics. To achieve this end we first make a comparison between two types of tableau proof systems, (graph & path), with the help of a scenario (The Friend's Puzzle). Having done that we show how to uniformly construct a tableau calculus for the combined logic using Governatori's labelled tableau system KEM. We conclude with a discussion on KEM's features. [ABSTRACT FROM AUTHOR]

In this work, we present a recently developed evaluation framework for video OCR specifically for English Text but could well be generalized for other languages as well. Earlier works include the development of an evaluation strategy for text detection and tracking in video, this work is a natural extension. We sucessfully port and use the ASR metrics used in the speech community here in the video domain. Further, we also show results on a small pilot corpus which involves 25 clips. Results obtained are promising and we believe that this is a good baseline and will encourage future participation in such evaluations. [ABSTRACT FROM AUTHOR]

The need for empirical evaluation metrics and algorithms is well acknowledged in the field of computer vision. The process leads to precise insights to understanding current technological capabilities and also helps in measuring progress. Hence designing good and meaningful performance measures is very critical. In this paper, we propose two comprehensive measures, one each for detection and tracking, for video domains where an object bounding approach to ground truthing can be followed. Thorough analysis explaining the behavior of the measures for different types of detection and tracking errors are discussed. Face detection and tracking is chosen as a prototype task where such an evaluation is relevant. Results on real data comparing existing algorithms are presented and the measures are shown to be effective in capturing the accuracy of the detection/tracking systems. [ABSTRACT FROM AUTHOR]

This paper addresses subtle aspects of graph mining using an SQL-based approach. The enhancements addressed in this paper include detection of cycles, effect of overlapping substructures on compression, and development of a minimum description length for the relational approach. Extensive performance evaluation has been conducted to evaluate the extensions. [ABSTRACT FROM AUTHOR]

The use of stereochemically constrained amino acids permits the design of short peptides as models for protein secondary structures. Amino acid residues that are restrained to a limited range of backbone torsion angles (ϕ-ψ) may be used as folding nuclei in the design of helices and β-hairpins. α-Amino-isobutyric acid (Aib) and related Cαα dialkylated residues are strong promoters of helix formation, as exemplified by a large body of experimentally determined structures of helical peptides. DPro-Xxx sequences strongly favor type II' turn conformations, which serve to nucleate registered β-hairpin formation. Appropriately positioned DPro-Xxx segments may be used to nucleate the formation of multistranded antiparallel β-sheet structures. Mixed (α/β) secondary structures can be generated by linking rigid modules of helices and β-hairpins. The approach of using stereochemically constrained residues promotes folding by limiting the local structural space at specific residues. Several aspects of secondary structure design are outlined in this chapter, along with commonly used methods of spectroscopic characterization. [ABSTRACT FROM AUTHOR]

We consider the problem of supporting bandwidth heterogeneity and congestion control in the context of P2P multicast streaming. We identify several challenges peculiar to the P2P setting including robustness concerns arising from peer unreliability and the ambiguity of packet loss as an indicator of congestion. We propose a hybrid parent- and child-driven bandwidth adaptation protocol that is designed in conjunction with a framework for robustness and that exploits application-level knowledge. [ABSTRACT FROM AUTHOR]

In this paper, we consider support for bandwidth-demanding applications such as video broadcasting using DHTs. Our investigations focus on the impact of heterogeneity in the outgoing bandwidth capabilities of nodes on Scribe, a representative and relatively mature DHT-based multicast protocol. We expose important issues that arise due to the mismatch between the ID space that underlies the DHT and the outgoing bandwidth constraints on nodes. [ABSTRACT FROM AUTHOR]

Our work is motivated by two observations about the state of networks today. Operators have little visibility into the end users' network experience while end users have little information or recourse when they encounter problems. We propose a system called NetProfiler, in which end hosts share network performance information with other hosts over a peer-to-peer network. The aggregated information from multiple hosts allows NetProfiler to profile the wide-area network, i.e., monitor end-to-end performance, and detect and diagnose problems from the perspective of end hosts. We define a set of attribute hierarchies associated with end hosts and their network connectivity. Information on the network performance and failures experienced by end hosts is then aggregated along these hierarchies, to identify patterns (e.g., shared attributes) that might be indicative of the source of the problem. In some cases, such sharing of information can also enable end hosts to resolve problems by themselves. The results from a 4-week-long Internet experiment indicate the promise of this approach. [ABSTRACT FROM AUTHOR]

In this paper, we present the idea of creating an intermediary model which is capable of being derived directly from the high-level, abstract model, but more closely resembles the actual implementation. The focus of our work is on the security properties of protocols. Not only do we show how an intermediary model can be constructed, but also how it can be used to automatically generate test sequences based on the security goals of the protocol being tested. Our aim is to show that by using this approach, we can derive test sequences suitable for a tester to use on a working implementation of the protocol. Keywords: protocol descriptions, security modelling, model-based testing, concrete test sequences. [ABSTRACT FROM AUTHOR]

In this article we present an application of decompositions of automata to obtain distributed controllers. The decomposition technique is derived from the classical method of partitions. This is then applied to the domain of discrete event systems. We show that it is possible to decompose a monolithic controller into smaller controllers which are non-conflicting. This is derived from the notion of decompositions via partitions. Some global state information is necessary to ensure that the joint behaviour of the component automata is identical to the original controller. The global state information required is identical to the global information present in Zielonka asynchronous automata. The joint behaviour of the component automata is shown to be non-conflicting. Keywords: Decompositions, Asynchronous Automata, Controllers. [ABSTRACT FROM AUTHOR]

Searching for similar objects (in terms of near and nearest neighbors) of a given query object from a large set is an essential task in many applications. Recent years have seen great progress towards efficient algorithms for this task. This paper takes a query language perspective, equipping SQL with the near and nearest search capability by adding a user-defined-predicate, called NN-UDP. The predicate indicates, among a set of objects, if an object is a near or nearest-neighbor of a given query object. The use of the NN-UDP makes the queries involving similarity searches intuitive to express. Unfortunately, traditional cost-based optimization methods that deal with traditional UDPs do not work well for such SQL queries. Better execution plans are possible with the introduction of a new operator, called NN-OP, which finds the near or nearest neighbors from a set of objects for a given query object. An optimization algorithm proposed in this paper can produce these plans that take advantage of the efficient search algorithms developed in recent years. To assess the proposed optimization algorithm, this paper focuses on applications that deal with streaming time series. Experimental results show that the optimization strategy is effective. [ABSTRACT FROM AUTHOR]

This paper describes an experimental study in the use of a composable proxy framework to improve the quality of interactive audio streams delivered to mobile hosts. Two forward error correction (FEC) proxylets are developed, one using block erasure codes, and the other using the GSM 06.10 encoding algorithm. Separately, each type of FEC improves the ability of the audio stream to tolerate errors in a wireless LAN environment. When composed in a single proxy, however, they cooperate to correct additional types of burst errors. Results are presented from a performance study conducted on a mobile computing testbed. [ABSTRACT FROM AUTHOR]

The utility of a recombinant vaccinia virus expression system for transient expression of genes was demonstrated in 1982 (1,2). Among a number of useful characteristics of this expression system are the capacity of the vaccinia virus genome to accommodate large genes (>20 kb pairs), availability of insertional sites on the viral genome yielding viable recombinant viruses, ability of the vaccinia virus to infect a wide range of mammalian hosts, cytoplasmic transcription and replication of the viral genome unlike many other expression systems, a relatively high level of recombinant proteins produced in infected cells, and the primary sequence-directed posttranslational modifications of recombinant proteins aim to native proteins (for a review, see ref. 3). As a first step in the construction of a recombinant vaccinia virus, the gene encoding a protein in the form of a cDNA is cloned into a plasmid vector under the control of an early or late vaccinia virus promoter (4-6), or a bacteriophage T7 promoter/the encephalomyocarditis virus 5′-untranslated leader sequence which would allow a cap independent mechanism of translation of the transcripts (7). Flanking the gene chosen for expression are DNA sequences representing portions of a nonessential viral gene such as that encoding the thymidine kinase in order to allow homologous recombination at the locus of the viral gene in vivo (6). The frequency with which the gene is integrated into the viral genome has been estimated to be about 0.1% (for a review, see ref. 3). In the original protocol for the isolation of a recombinant vaccinia virus (6), cell monolayers are infected with the wild-type virus (WR strain) and transfected with the plasmid DNA encoding the gene of interest. Since insertion of the gene of interest at the viral thymidine kinase (TK) gene locus results in recombinant viruses with the TK− phenotype, plaque isolates of recombinant viruses are selected in the presence of 5-bromodeoxyuridine (5-BrdU). The conditions chosen for selection in the presence of this analog of thymidine are lethal to replication of the wild-type virus owing to incorporation of the phosphorylated form into the viral genome, but not to the recombinant virus deficient in TK. The cell lysates containing the wild-type and recombinant viruses at appropriate dilutions are used to infect cell monolayers of human TK− cells, and then overlaid with growth medium containing agarose and 5-BrdU to prevent spreading of recombinant virus plaques and inhibit replication of the wild-type virus, respectively. A second agarose overlay containing the 5-BrdU and the neutral red stain is used to enable one to visualize recombinant virus plaques (6). A single plaque results from a productively infected cell and the cell-to-cell spread of the virus, and an agarose overlay localizes each of these plaques on a mono-layer. Since a plaque could consist of either a recombinant virus or a spontaneous TK− mutant virus often present as a contaminant in the cell lysates, a suitable hybridization technique is employed in the screening protocol for isolation of recombinants (6). [ABSTRACT FROM AUTHOR]