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Search Results: 1 - 10 of 302370 matches for " Michele J. Mann "
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The Mathematics in the Social Studies Textbook: A Critical Content Analysis and Implications for Students’ Reasoning  [PDF]
Flávio S. Azevedo, Michele J. Mann
Creative Education (CE) , 2019, DOI: 10.4236/ce.2019.101001
Abstract: We report on a case study of the?mathematical?content of a 10th?grade?social studies?textbook. We develop our case in three analytical steps. First, we identify, describe, and categorize the full range of mathematics in the book. Put simply, we ask: What mathematical forms (e.g., Cartesian graphs and problems) do we find and what kinds of mathematical work do they require? Second, we characterize and critically evaluate the mathematics content in the textbook, focusing in particular on the kinds of mathematics literacy and student reasoning that the book fosters. Third and finally, we operationalize a measure of the “density” of mathematics in the textbook—that is, an estimate of the presence and pervasiveness of mathematical objects and practices relative to other disciplinary contentsand track how such “density” has changed over the past three editions of the same volume. Doing so helps us further contextualize and elaborate the prior analyses, but also surfaces shifts in the patterns of mathematics presence in that textbook series, including the growing encroachment of mathematics exercising and visual/representational presence.
Phosphoproteomes of Strongylocentrotus purpuratus shell and tooth matrix: identification of a major acidic sea urchin tooth phosphoprotein, phosphodontin
Karlheinz Mann, Albert J Poustka, Matthias Mann
Proteome Science , 2010, DOI: 10.1186/1477-5956-8-6
Abstract: The present report contains the determination of test (shell) and tooth organic matrix phosphoproteomes. Altogether 34 phosphoproteins were identified in the biomineral organic matrices. Most phosphoproteins were specific for one compartment, only two were identified in both matrices. The sea urchin phosphoproteomes contained several obvious orthologs of mammalian proteins, such as a Src family tyrosine kinase, protein kinase C-delta 1, Dickkopf-1 and other signal transduction components, or nucleobindin. In most cases phosphorylation sites were conserved between sea urchin and mammalian proteins. However, the majority of phosphoproteins had no mammalian counterpart. The most interesting of the sea urchin-specific phosphoproteins, from the perspective of biomineralization research, was an abundant highly phosphorylated and very acidic tooth matrix protein composed of 35 very similar short sequence repeats, a predicted N-terminal secretion signal sequence, and an Asp-rich C-terminal motif, contained in [Glean3:18919].The 64 phosphorylation sites determined represent the most comprehensive list of experimentally identified sea urchin protein phosphorylation sites at present and are an important addition to the recently analyzed Strongylocentrotus purpuratus shell and tooth proteomes. The identified phosphoproteins included a major, highly phosphorylated protein, [Glean3:18919], for which we suggest the name phosphodontin. Although not sequence-related to such highly phosphorylated acidic mammalian dental phosphoproteins as phosphoryn or dentin matrix protein-1, phosphodontin may perform similar functions in the sea urchin tooth. More than half of the detected proteins were not previously identified at the protein level, thus confirming the existence of proteins only known as genomic sequences previously.Sea urchin is an important model organism for developmental biology and in particular skeletogenesis, providing insight into common principles of biomineralization [1-
In-depth, high-accuracy proteomics of sea urchin tooth organic matrix
Karlheinz Mann, Albert J Poustka, Matthias Mann
Proteome Science , 2008, DOI: 10.1186/1477-5956-6-33
Abstract: We identified 138 proteins in the matrix of tooth powder. Only 56 of these proteins were previously identified in the matrices of test (shell) and spine. Among the novel components was an interesting group of five proteins containing alanine- and proline-rich neutral or basic motifs separated by acidic glycine-rich motifs. In addition, four of the five proteins contained either one or two predicted Kazal protease inhibitor domains. The major components of tooth matrix were however largely identical to the set of spicule matrix proteins and MSP130-related proteins identified in test (shell) and spine matrix. Comparison of the matrices of crushed teeth to intact teeth revealed a marked dilution of known intracrystalline matrix proteins and a concomitant increase in some intracellular proteins.This report presents the most comprehensive list of sea urchin tooth matrix proteins available at present. The complex mixture of proteins identified may reflect many different aspects of the mineralization process. A comparison between intact tooth matrix, presumably containing odontoblast remnants, and crushed tooth matrix served to differentiate between matrix components and possible contributions of cellular remnants. Because LC-MS/MS-based methods directly measures peptides our results validate many predicted genes and confirm the existence of the corresponding proteins. Knowledge of the components of this model system may stimulate further experiments aiming at the elucidation of structure, function, and interaction of biomineral matrix components.The masticatory apparatus of sea urchins (Aristotle's lantern) contains five elongated teeth that have been attractive models for studying biomineralization processes. The constant wearing away of the tips is compensated by continuous tooth growth at the base. The cells responsible for tooth growth arise at the aboral end of the tooth, the plumula, and form multinucleated syncytia, which cover the entire tooth until they are remov
The sea urchin (Strongylocentrotus purpuratus) test and spine proteomes
Karlheinz Mann, Albert J Poustka, Matthias Mann
Proteome Science , 2008, DOI: 10.1186/1477-5956-6-22
Abstract: We identified 110 proteins as components of sea urchin test and spine organic matrix. Fourty of these proteins occurred in both compartments while others were unique to their respective compartment. More than 95% of the proteins were detected in sea urchin skeletal matrices for the first time. The most abundant protein in both matrices was the previously characterized spicule matrix protein SM50, but at least eight other members of this group, many of them only known as conceptual translation products previously, were identified by mass spectrometric sequence analysis of peptides derived from in vitro matrix degradation. The matrices also contained proteins implicated in biomineralization processes previously by inhibition studies using antibodies or specific enzyme inhibitors, such as matrix metalloproteases and members of the mesenchyme-specific MSP130 family. Other components were carbonic anhydrase, collagens, echinonectin, a α2-macroglobulin-like protein and several proteins containing scavenger receptor cysteine-rich domains. A few possible signal transduction pathway components, such as GTP-binding proteins, a semaphorin and a possible tyrosine kinase were also identified.This report presents the most comprehensive list of sea urchin skeletal matrix proteins available at present. The complex mixture of proteins identified in matrices of the sea urchin skeleton may reflect many different aspects of the mineralization process. Because LC-MS/MS-based methods directly measures peptides our results validate many predicted genes and confirm the existence of the corresponding proteins. Considering the many newly identified matrix proteins, this proteomic study may serve as a road map for the further exploration of biomineralization processes in an important model organism.Biominerals contain an organic matrix which is believed to organize a 3-dimensional framework for mineralization, to provide crystal nucleation sites, to contain molecules which determine crystal s
Baryonic B decays
J. Schümann
Physics , 2005,
Abstract: We summarize recent results of baryonic B decays from Belle and BaBar. The results from Belle are based on 140 /fb and results from BaBar are based on 81 /fb of data collected at the Upsilon(4S) resonance at KEKB or PEPII respectively. We report the results of two- and three-body baryonic B decays as well as searches for pentaquarks. The three-body baryonic B decays display an enhancement in the low mass region, which is not in agreement with general phase space expectations.
Factors Contributing to the 2005-Present, Rapid Rise in Lake Levels, Dominican Republic and Haiti (Hispaniola)  [PDF]
Vanshan D. Wright, Matthew J. Hornbach, Cecilia Mchugh, Paul Mann
Natural Resources (NR) , 2015, DOI: 10.4236/nr.2015.68045
Abstract: Lakes Enriquillo and Azuei, the two largest lakes in Hispaniola and in the Caribbean, have risen 10 and 5 m respectively within the last 8 years. Higher lake levels have submerged towns, road systems, agricultural lands and utilities, and have threatened to submerge the major overland highway that connects the Dominican Republic and Haiti. In this study, we use CHIRP seismic data, satellite imagery, and regional meteorological data to quantify and assess controls on the recent lake level rises. Although data are limited, the analyses indicate that the lakes’ water level changes may be attributed to a combination of increased rainfall and natural or man-made changes to the hydraulic connectivity of the various water bodies within the drainage basin. We show that a weak correlation exists between changes in Lake Enriquillo’s and Azuei’s water levels and precipitation rates (0.2 and 0.08 respectively, 1984-2012) and that both lakes experience periods of anti-correlation where, for example, water level drops at Lake Azuei (~20 masl) coincide with water level rises at Lake Enriquillo (41 mbsl). From these observations, we propose that the lakes experience intermittent periods of hydraulic connectivity along reactivated or newly developed stratigraphic-controlled sub-surface transport pathways. We also note that moderately small earthquakes along the large active fault system that extends through both lakes may promote or limit hydraulic conductivity on decadal or shorter time scales. The extents to which recent earthquakes have triggered changes in groundwater flow at this site remain unclear but represent an important topic of future research.
Identification of transposon insertion mutants of Francisella tularensis tularensis strain Schu S4 deficient in intracellular replication in the hepatic cell line HepG2
Aiping Qin, Barbara J Mann
BMC Microbiology , 2006, DOI: 10.1186/1471-2180-6-69
Abstract: We constructed a stable transposon mutagenesis library of virulent strain Schu S4 using a derivative of the EZ::TN transposon system?. Approximately 2000 mutants were screened for the inability to invade, and replicate in the hepatic carcinoma cell line HepG2. These mutants were also tested for replication within the J774.1 macrophage-like cell line.Eighteen mutants defective in intracellular replication in HepG2 cells were identified. Eight of these mutants were auxotrophs; seven had mutations in nucleotide biosynthesis pathways. The remaining mutants had insertions in genes that were predicted to encode putative transporters, enzymes involved in protein modification and turnover, and hypothetical proteins. A time course of the intracellular growth of a pyrB mutant revealed that this mutant was only able to grow at low levels within HepG2 cells but grew like wild-type bacteria in J774.1 cells. This pyrB mutant was also attenuated in mice.This is the first reported large-scale mutagenesis of a type A strain of F. tularensis and the first identification of mutants specifically defective in intracellular growth in a hepatic cell line. We have identified several genes and pathways that are key for the survival and growth of F. tularensis in a hepatic cell line, and a number of novel intracellular growth-defective mutants that have not been previously characterized in other pathogens. Further characterization of these mutants will help provide a better understanding of the pathogenicity of F. tularensis, and may have practical applications as targets for drugs or attenuated vaccines.Francisella tularensis is a gram-negative bacterium that causes a potentially life-threatening disease called tularemia [1]. There are several subspecies of Francisella but F. tularensis tularensis and F. tularensis holarctica, also known as Type A and Type B, respectively, are the most prevalent. Type A isolates have been classified as a category A select agent of biological warfare. They a
Generation of large scale electric fields in coronal flare circuits
Hakan ?nel,Gottfried J. Mann
Physics , 2009,
Abstract: A large number of energetic electrons are generated during solar flares. They carry a substantial part of the flare released energy but how these electrons are created is not fully understood yet. This paper suggests that plasma motion in an active region in the photosphere is the source of large electric currents. These currents can be described by macroscopic circuits. Under special circumstances currents can establish in the corona along magnetic field lines. The energy released by these currents when moderate assumptions for the local conditions are made, is found be comparable to the flare energy.
Search for B decays into eta' rho, eta' K*, eta' phi, eta' omega and eta' eta(') at Belle
J. Schümann,for the Belle Collaboration
Physics , 2007, DOI: 10.1103/PhysRevD.75.092002
Abstract: We report on a search for the exclusive two-body charmless hadronic B meson decays B-> eta' rho, B-> eta' K*, B-> eta' phi, B-> eta' omega and B->eta' eta('). The results are obtained from a data sample containing 535 x 10^6 BBbar pairs that were collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ e- collider. We find no significant signals and report upper limits in the range 0.5-6.5 x 10^{-6} for all of the above decays.
Quasilocal Thermodynamics of Dilaton Gravity coupled to Gauge Fields
J. Creighton,R. B. Mann
Physics , 1995, DOI: 10.1103/PhysRevD.52.4569
Abstract: We consider an Einstein-Hilbert-Dilaton action for gravity coupled to various types of Abelian and non-Abelian gauge fields in a spatially finite system. These include Yang-Mills fields and Abelian gauge fields with three and four-form field strengths. We obtain various quasilocal quantities associated with these fields, including their energy and angular momentum, and develop methods for calculating conserved charges when a solution possesses sufficient symmetry. For stationary black holes, we find an expression for the entropy from the micro-canonical form of the action. We also find a form of the first law of black hole thermodynamics for black holes with the gauge fields of the type considered here.
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