Intrinsic motivation in the classroom: Increasing learning and retention

A growing body of research suggests that intrinsic motivation and self-determination are key factors in academic achievement and success. The present study investigated whether children learned and retained information better when taught a social skills lesson using a self-determining approach, rather than a traditional directive lesson plan. In particular, this study examined whether lesson plans that included choice and autonomy support would affect students\u27 intrinsic motivation for the task, and improve their learning and retention over time. Fifty-six fourth grade students from a large suburban school district in upstate New York participated. Significant group differences were found on a pre-test measure indicating that the classes differed on their prior knowledge of the topic. There were no significant differences on the post-test measure however. Two groups, those that participated in a role-play activity and those that had a choice, improved their scores from pre to post test more than the third group. Additionally, intrinsic motivation was positively correlated with the student\u27s change in scores from pre-test to post-test. While the correlation was not significant, it indicated a positive relationship between intrinsic motivation and information learned and retained over time. The implications of these findings are discussed

The Study of Procurement Logistic with Focus on Purchasing

Diplomová práce je zaměřena na zlepšení logistiky opatřování ve firmě, která působí ve strojírenském průmyslu. Práce řeší tento problém zavedení vnitřních auditů a systému hodnotícího spolehlivost jednotlivých dodavatelů.This graduation theses focususes on improvement of logistician acquisition in company, which operates in machine industry. The theses solves this problem with application of internal audits and by use of system which valuates reliability of individual suppliers.

Recognition of peptidoglycan and b-lactam antibiotics by the extracellular domain of the Ser/Thr protein kinase StkP from Streptococcus pneumoniae

The eukaryotic-type serine/threonine kinase StkP from Streptococcus pneumoniae is an important signal-transduction element that regulates the expression of numerous pneumococcal genes. We have expressed the extracellular C-terminal domain of StkP kinase (C-StkP), elaborated a three-dimensional structural model and performed a spectroscopical characterization of its structure and stability. Biophysical experiments show that C-StkP binds to synthetic samples of the cell wall peptidoglycan (PGN) and to β-lactam antibiotics, which mimic the terminal portions of the PGN stem peptide. This is the first experimental report on the recognition of a minimal PGN unit by a PASTA-containing kinase, suggesting that non-crosslinked PGN may act as a signal for StkP function and pointing to this protein as an interesting target for β-lactam antibiotics

Structural and photophysical characterisation of coordination and optical isomers of mononuclear ruthenium(II) polypyridyl 1,2,4-triazole complexes

The X-ray crystal structure of the N2 isomers of the Ru(bipy)2 complexes of Hphpztr (1) and Hpztr (2), (bipy = 2,2'-bipyridine, Hphpztr = 2-(5'-phenyl-4'H-[1,2,4]triazol-3'-yl)pyrazine and Hpztr = 2-(4'H-[1,2,4]triazol-3'-yl)pyrazine) are reported. The molecular structure obtained for 2 demonstrates an interesting structural aspect in the sharing of a single proton between two molecular units. The isolation of the Δ and Λ stereoisomers of 1 and [Ru(phen)2(pztr)]+ (phen = 1,10-phenanthroline) (3) by semipreparative HPLC is also reported. The compounds obtained are characterised by electronic spectroscopy and particular attention is paid to the photophysical properties of Δ and Λ isomers of 1 and 3, in chiral enantiopure and racemic solvents

Reaction products and the X-ray structure of AmpDh2, a virulence determinant of Pseudomonas aeruginosa

4 pags, 4 figs. -- Supporting Information is available at the Publisher web.The zinc protease AmpDh2 is a virulence determinant of Pseudomonas aeruginosa, a problematic human pathogen. The mechanism of how the protease manifests virulence is not known, but it is known that it turns over the bacterial cell wall. The reaction of AmpDh2 with the cell wall was investigated, and nine distinct turnover products were characterized by LC/MS/MS. The enzyme turns over both the cross-linked and noncross-linked cell wall. Three high-resolution X-ray structures, the apo enzyme and two complexes with turnover products, were solved. The X-ray structures show how the dimeric protein interacts with the inner leaflet of the bacterial outer membrane and that the two monomers provide a more expansive surface for recognition of the cell wall. This binding surface can accommodate the 3D solution structure of the cross-linked cell wall. © 2013 American Chemical Society.This work was supported by a grant from the NIH (GM61629) and by grants BFU2011-25326 (the Spanish Ministry of Economy and Competitiveness) and S2010/BMD-2457 (the Government of Community of Madrid). The Mass Spectrometry & Proteomics Facility of the University of Notre Dame is supported by grant CHE0741793 from the NSF

Integrative structural biology of the penicillin-binding protein-1 from Staphylococcus aureus, an essential component of the divisome machinery

14 pags., 6 figs., 2 tabs.The penicillin-binding proteins are the enzyme catalysts of the critical transpeptidation crosslinking polymerization reaction of bacterial peptidoglycan synthesis and the molecular targets of the penicillin antibiotics. Here, we report a combined crystallographic, small-angle X-ray scattering (SAXS) in-solution structure, computational and biophysical analysis of PBP1 of Staphylococcus aureus (saPBP1), providing mechanistic clues about its function and regulation during cell division. The structure reveals the pedestal domain, the transpeptidase domain, and most of the linker connecting to the “penicillin-binding protein and serine/threonine kinase associated” (PASTA) domains, but not its two PASTA domains, despite their presence in the construct. To address this absence, the structure of the PASTA domains was determined at 1.5 Å resolution. Extensive molecular-dynamics simulations interpret the PASTA domains of saPBP1 as conformationally mobile and separated from the transpeptidase domain. This conclusion was confirmed by SAXS experiments on the full-length protein in solution. A series of crystallographic complexes with β-lactam antibiotics (as inhibitors) and penta-Gly (as a substrate mimetic) allowed the molecular characterization of both inhibition by antibiotics and binding for the donor and acceptor peptidoglycan strands. Mass-spectrometry experiments with synthetic peptidoglycan fragments revealed binding by PASTA domains in coordination with the remaining domains. The observed mobility of the PASTA domain in saPBP1 could play a crucial role for in vivo interaction with its glycosyltransferase partner in the membrane or with other components of the divisome machinery, as well as for coordination of transpeptidation and polymerization processes in the bacterial divisome.The work in the USA was supported by grants AI104987 (to SM)and AI116548 (to MC) from the NIH. The work in Spain was fundedby a grant from the Spanish Ministry of Science, Innovation and Competitiveness (BFU2017-90030-P and PID2020-115331GB-100 to JAH). We thank the staff from ALBA and Diamond Light Sourcesynchrotrons for help during X-ray and SAXS data collection,respectivel

Crystal structures of bacterial peptidoglycan amidase AmpD and an unprecedented activation mechanism

9 pags, 5 figs, 2 tabsAmpD is a cytoplasmic peptidoglycan (PG) amidase involved in bacterial cell-wall recycling and in induction of β-lactamase, a key enzyme of β-lactam antibiotic resistance. AmpD belongs to the amidase-2 family that includes zinc-dependent amidases and the peptidoglycan-recognition proteins (PGRPs), highly conserved pattern-recognition molecules of the immune system. Crystal structures of Citrobacter freundii AmpD were solved in this study for the apoenzyme, for the holoenzyme at two different pH values, and for the complex with the reaction products, providing insights into the PG recognition and the catalytic process. These structures are significantly different compared with the previously reported NMR structure for the same protein. TheNMRstructure does not possess an accessible active site and shows the protein in what is proposed herein as an inactive "closed" conformation. The transition of the protein from this inactive conformation to the active "open" conformation, as seen in the x-ray structures, was studied by targeted molecular dynamics simulations, which revealed large conformational rearrangements (as much as 17 Å ) in four specific regions representing one-third of the entire protein. It is proposed that the large conformational change that would take the inactive NMR structure to the active x-ray structure represents an unprecedented mechanism for activation of AmpD. Analysis is presented to argue that this activation mechanism might be representative of a regulatory process for other intracellular members of the bacterial amidase-2 family of enzymes. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.This work was supported, in whole or in part, by the National Institutes of Health. This work was also supported by grants from the Spanish Ministry of Science and Technology (BFU2008-01711), EU-CP223111 (CARE-PNEUMO, European Union), and the COMBACT program (S-BIO-0260/2006). We acknowledge the Spanish Ministerio de Ciencia e Innovación (PI201060E013) and Consejo Superior de Investigaciones Científicas for financial support and for provision of synchrotron radiation facilitie

How Allosteric Control of Staphylococcus aureus Penicillin-Binding Protein 2a Enables Methicillin-Resistance and Physiological Function

The expression of penicillin binding protein 2a (PBP2a) is the basis for the broad clinical resistance to the β-lactam antibiotics by methicillin-resistant Staphylococcus aureus (MRSA). The highmolecular mass penicillin binding proteins of bacteria catalyze in separate domains the transglycosylase and transpeptidase activities required for the biosynthesis of the peptidoglycan polymer that comprises the bacterial cell wall. In bacteria susceptible to β-lactam antibiotics, the transpeptidase activity of their penicillin binding proteins (PBPs) is lost as a result of irreversible acylation of an active site serine by the β-lactam antibiotics. In contrast, the PBP2a of MRSA is resistant to β-lactam acylation and successfully catalyzes the DD-transpeptidation reaction necessary to complete the cell wall. The inability to contain MRSA infection with β-lactam antibiotics is a continuing public health concern. We report herein the identification of an allosteric binding domain - a remarkable 60 Å distant from the DD-transpeptidase active site - discovered by crystallographic analysis of a soluble construct of PBP2a. When this allosteric site is occupied, a multiresidue conformational change culminates in the opening of the active site to permit substrate entry. This same crystallographic analysis also reveals the identity of three allosteric ligands: muramic acid (a saccharide component of the peptidoglycan), the cell wall peptidoglycan, and ceftaroline, a recently approved anti-MRSA β-lactam antibiotic. The ability of an anti-MRSA β-lactam antibiotic to stimulate allosteric opening of the active site, thus predisposing PBP2a to inactivation by a second β-lactam molecule, opens an unprecedented realm for β-lactam antibiotic structure-based design.Fil: Otero, Lisandro Horacio. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Rojas Altuve, Alzoray. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Llarrull, Leticia Irene. University of Notre Dame; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Carrasco López, Cesar. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Kumarasiri, Malika. University of Notre Dame; Estados UnidosFil: Lastochkin, Elena. University of Notre Dame; Estados UnidosFil: Fishovitz, Jennifer. University of Notre Dame; Estados UnidosFil: Dawley, Matthew. University of Notre Dame; Estados UnidosFil: Hesek, Dusan. University of Notre Dame; Estados UnidosFil: Lee, Mijoon. University of Notre Dame; Estados UnidosFil: Johnson, Jarrod W.. University of Notre Dame; Estados UnidosFil: Fisher, Jed F.. University of Notre Dame; Estados UnidosFil: Chang, Mayland. University of Notre Dame; Estados UnidosFil: Mobashery, Shahriar. University of Notre Dame; Estados UnidosFil: Hermoso, Juan A.. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; Españ

How allosteric control of Staphylococcus aureus penicillin binding protein 2a enables methicillin resistance and physiological function

6 pags, 4 figs, 1 tabThe expression of penicillin binding protein 2a (PBP2a) is the basis for the broad clinical resistance to the β-lactam antibiotics by methicillin-resistant Staphylococcus aureus (MRSA). The highmolecular mass penicillin binding proteins of bacteria catalyze in separate domains the transglycosylase and transpeptidase activities required for the biosynthesis of the peptidoglycan polymer that comprises the bacterial cell wall. In bacteria susceptible to β-lactam antibiotics, the transpeptidase activity of their penicillin binding proteins (PBPs) is lost as a result of irreversible acylation of an active site serine by the β-lactam antibiotics. In contrast, the PBP2a of MRSA is resistant to β-lactam acylation and successfully catalyzes the DD-transpeptidation reaction necessary to complete the cell wall. The inability to contain MRSA infection with β-lactam antibiotics is a continuing public health concern. We report herein the identification of an allosteric binding domain - a remarkable 60 Å distant from the DD-transpeptidase active site - discovered by crystallographic analysis of a soluble construct of PBP2a. When this allosteric site is occupied, a multiresidue conformational change culminates in the opening of the active site to permit substrate entry. This same crystallographic analysis also reveals the identity of three allosteric ligands: muramic acid (a saccharide component of the peptidoglycan), the cell wall peptidoglycan, and ceftaroline, a recently approved anti-MRSA β-lactam antibiotic. The ability of an anti-MRSA β-lactam antibiotic to stimulate allosteric opening of the active site, thus predisposing PBP2a to inactivation by a second β-lactam molecule, opens an unprecedented realm for β-lactam antibiotic structure-based design.Work in the United States was supported by National Institutes of Health Grants AI090818 and AI104987, and work in Spain was supported by Grants BFU2011-25326 (from the Spanish Ministry of Economy and Competitiveness) and S2010/BMD-2457 (from the Autonomous Government of Madrid)