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1.
Proc Natl Acad Sci U S A ; 117(37): 22665-22667, 2020 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-32868432

RESUMEN

Programs seeking to transform undergraduate science, technology, engineering, and mathematics courses often strive for participating faculty to share their knowledge of innovative teaching practices with other faculty in their home departments. Here, we provide interview, survey, and social network analyses revealing that faculty who use innovative teaching practices preferentially talk to each other, suggesting that greater steps are needed for information about innovative practices to reach faculty more broadly.

2.
Int J STEM Educ ; 4(1): 8, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-30631664

RESUMEN

BACKGROUND: Calls to improve student learning and increase the number of science, technology, engineering, and math (STEM) college and university graduates assert the need for widespread adoption of evidence-based instructional practices in undergraduate STEM courses. For successful reforms to take hold and endure, it is likely that a significant shift in culture around teaching is needed. This study seeks to describe the initial response of faculty to an effort to shift teaching norms, with a long-term goal of altering the culture around teaching and learning in STEM. While the effort was envisioned and led at the institutional level, dialog about the proposed change and actions taken by faculty was emergent and supported within departments. RESULTS: Faculty identify a variety of barriers to proposed changes in teaching practice; however, faculty also identify a variety of drivers that might help the institution alter teaching and learning norms. Analysis of faculty responses reveals 18 categories of barriers and 15 categories of drivers in faculty responses. Many of the barrier and driver categories were present in each department's responses; however, the distribution and frequency with which they appear reveals departmental differences that are important for moving forward with strategies to change teaching practice. CONCLUSIONS: Addressing faculty's barriers to change is essential, but identifying and leveraging faculty's drivers for the change is potentially equally important in efforts to catalyze changes that are supported or constrained by the local context. Further, the collection of faculty perspectives opens a dialog around the current and future state of teaching, an important step in laying the groundwork for change. Departmental differences in barriers and drivers make clear the importance of "knowing" the local contexts so strategies adopted by departments can be appropriately tailored. Results are discussed in light of what kind of strategies might be employed to effect changes in STEM education.

3.
Int J STEM Educ ; 4(1): 25, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-30631681

RESUMEN

BACKGROUND: The efficacy of active learning within STEM education is clear, and many institutions are working to help faculty adopt evidence-based instructional practices (EBIPs) which can promote active learning. In order to know the current status of our campus regarding these goals, measures of current instructional climate and the adoption of evidence-based instructional practices (EBIPs) are desired. RESULTS: Using a campus-wide online survey approach with remuneration for faculty participants, the 28-item current instructional climate survey (CICS) and the 6-item EBIP adoption scale were developed. When CICS and EBIP adoption scale outcomes are compared, patterns emerge which reflect the climate, conditions, and personal characteristics of faculty at different stages of EBIP adoption. CONCLUSIONS: Although not causal relationships, understanding both climate and personal change characteristics can be helpful to campus change agents in assessing the current STEM landscape of faculty practices.

4.
Inorg Chem ; 46(4): 1259-67, 2007 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-17291118

RESUMEN

Second-coordination sphere effects such as hydrogen bonding and steric constraints that provide for specific geometric configurations play a critical role in tuning the electronic structure of metalloenzyme active sites and thus have a significant effect on their catalytic efficiency. Crystallographic characterization of vertebrate and plant sulfite oxidase (SO) suggests that an average O(oxo)-Mo-S(Cys)-C dihedral angle of approximately 77 degrees exists at the active site of these enzymes. This angle is slightly more acute (approximately 72 degrees) in the bacterial sulfite dehydrogenase (SDH) from Starkeya novella. Here we report the synthesis, crystallographic, and electronic structural characterization of Tp*MoO(mba) (where Tp* = (3,5-dimethyltrispyrazol-1-yl)borate; mba = 2-mercaptobenzyl alcohol), the first oxomolybdenum monothiolate to possess an O(ax)-Mo-S(thiolate)-C dihedral angle of approximately 90 degrees . Sulfur X-ray absorption spectroscopy clearly shows that O(ax)-Mo-S(thiolate)-C dihedral angles near 90 degrees effectively eliminate covalency contributions to the Mo(xy) redox orbital from the thiolate sulfur. Sulfur K-pre-edge X-ray absorption spectroscopy intensity ratios for the spin-allowed S(1s) --> Sv(p) + Mo(xy) and S(1s) --> Sv(p) + Mo(xz,yz) transitions have been calibrated by a direct comparison of theory with experiment to yield thiolate Sv(p) orbital contributions, c(j)(2), to the Mo(xy) redox orbital and the Mo(xz,yz) orbital set. Furthermore, these intensity ratios are related to a second coordination sphere structural parameter, the O(oxo)-Mo-S(thiolate)-C dihedral angle. The relationship between Mo-S(thiolate) and Mo-S(dithiolene) covalency in oxomolydenum systems is discussed, particularly with respect to electron-transfer regeneration in SO.


Asunto(s)
Cisteína/química , Molibdeno/química , Compuestos Organometálicos/química , Óxidos/química , Compuestos de Sulfhidrilo/química , Sulfito-Oxidasa/química , Azufre/química , Sitios de Unión , Transporte de Electrón , Enlace de Hidrógeno , Estructura Molecular , Oxidación-Reducción , Análisis Espectral , Sulfito-Oxidasa/metabolismo
5.
Cardiovasc Toxicol ; 5(4): 365-76, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16382174

RESUMEN

Carbonyl reductase (CR) catalyzes the nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reduction of several carbonyls. Anthracyclines used to treat cancer are reduced by CR at the C13 carbonyl and the resulting metabolites are implicated in the cardiotoxicity associated with anthracycline therapy. CR also is believed to have a role in detoxifying quinones, raising the question whether CR catalyzes reduction of anthracycline quinones. Steady-state kinetic studies were done with several anthraquinone-containing compounds, including 13-deoxydoxorubicin and daunorubicinol, which lack the C13 carbonyl, thus unmasking the anthraquinone for study. k(cat) and k(cat)/K(m) values for 13-deoxydoxorubicin and daunorubicinol were nearly identical, indicating that that the efficiency of quinone reduction was unaffected by the differences at the C13 position. k(cat) and k(cat)/K(m) values were much smaller for the analogs than for the parent compounds, suggesting that the C13 carbonyl is preferred as a substrate over the quinone. CR also reduced structurally related quinone molecules with less favorable catalytic efficiency. Modeling studies with doxorubicin and carbonyl reductase revealed that methionine 234 sterically hinder the rings adjacent to the quinone, thus accounting for the lower catalytic efficiency. Reduction of the anthraquinones may further define the role of CR in anthracycline metabolism and may influence anthracycline cytotoxic and cardiotoxic mechanisms.


Asunto(s)
Oxidorreductasas de Alcohol/metabolismo , Daunorrubicina/análogos & derivados , Doxorrubicina/análogos & derivados , Oxidorreductasas de Alcohol/aislamiento & purificación , Animales , Antraquinonas/química , Daunorrubicina/química , Daunorrubicina/metabolismo , Doxorrubicina/metabolismo , Humanos , Modelos Moleculares , Oxidación-Reducción , Estructura Terciaria de Proteína , Proteínas Recombinantes
6.
Cardiovasc Toxicol ; 5(3): 269-83, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16244372

RESUMEN

Utilizing a model of chronic doxorubicin cardiomyopathy, this study examines the relationship between changes in expression and function of calcium handling proteins and contractile dysfunction. A possible mechanism to account for this relationship is suggested. New Zealand white rabbits were injected with either doxorubicin (1 mg/kg, twice weekly for 8 wk) or 0.9% NaCl. Gene transcript, protein levels, and the function of several proteins from the left ventricle were assessed. Protein levels of sarcoplasmic reticulum (SR) Ca2+ transporting ATPase (SERCA2a and b), Ca2+ release channel (RYR2), calsequestrin, Na/Ca exchanger, mRNA levels of RYR2, and [3H]-ryanodine binding (B(max)) to RYR2 were significantly decreased in doxorubicin-treated rabbits; protein levels of phospholamban, dihydropyridine receptor alpha2 subunit, and SR Ca2+ loading rates were not decreased. However, only protein levels of SERCA2 and RYR2, mRNA levels of RYR2, and Bmax of RYR2 significantly regressed with left-ventricular fractional shortening. Analysis of contractile function of atrial preparations isolated from doxorubicin-treated rabbits revealed that doxorubicin diminished contractility (dF/dt) of rest-potentiated contractions consistent with SR dysfunction. Serum concentrations of free triiodothyronine (T3) decreased in doxorubicin-treated rabbits. Our results suggest that chronic doxorubicin administration in the rabbit causes a SR-dependent contractile dysfunction that may result, in part, from decreased T3.


Asunto(s)
Antibióticos Antineoplásicos/toxicidad , Calcio/metabolismo , Doxorrubicina/toxicidad , Cardiopatías/inducido químicamente , Retículo Sarcoplasmático/efectos de los fármacos , Triyodotironina/metabolismo , Animales , Anticuerpos Monoclonales , Western Blotting , Canales de Calcio Tipo L/metabolismo , Proteínas de Unión al Calcio/metabolismo , ATPasas Transportadoras de Calcio/metabolismo , Calsecuestrina/metabolismo , Electrocardiografía , Cardiopatías/fisiopatología , Masculino , Contracción Miocárdica/efectos de los fármacos , Ensayos de Protección de Nucleasas , Proteínas/metabolismo , ARN/biosíntesis , ARN/genética , Conejos , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Sarcolema/efectos de los fármacos , Sarcolema/metabolismo , Retículo Sarcoplasmático/metabolismo , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico , Intercambiador de Sodio-Calcio/metabolismo , Tirotropina/sangre , Triyodotironina/sangre
7.
Protein Sci ; 14(6): 1526-37, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15930001

RESUMEN

Fibrillar collagens are the principal structural molecules of connective tissues. The assembly of collagen fibrils is regulated by quantitatively minor fibrillar collagens, types V and XI. A unique amino-terminal propeptide domain of these collagens has been attributed this regulatory role. The structure of the amino terminal propeptide has yet to be determined. Low sequence similarity necessitated a secondary structure-based method to carry out homology modeling based upon the determined structure of LNS family members, named for a common structure in the laminin LG5 domain, the neurexin 1B domain and the sex hormone binding globulin. Distribution of amino acids within the model suggested glycosaminoglycan interaction and calcium binding. These activities were tested experimentally. Sequence analyses of existing genes for collagens indicate that 16 known collagen alpha chains may contain an LNS domain. A similar approach may prove useful for structure/function studies of similar domains in other collagens with similar domains. This will provide mechanistic details of the organization and assembly of the extracellular matrix and the underlying basis of structural integrity in connective tissues. The absolute requirement for collagen XI in skeletal growth is indicated by collagen XI deficiencies such as chondrodystrophies found in the cho/cho mouse and in humans with Stickler syndrome.


Asunto(s)
Colágeno Tipo XI/química , Secuencia de Aminoácidos , Animales , Humanos , Datos de Secuencia Molecular , Estructura Terciaria de Proteína , Homología de Secuencia de Aminoácido
8.
Mol Pharmacol ; 67(5): 1505-12, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15705743

RESUMEN

Anthracycline therapy is associated with a life-threatening but poorly understood cardiotoxicity. Effects of treatment are consistent with drug-induced disruption of cardiac sarcoplasmic reticulum (SR) calcium homeostasis, including inhibition of calcium release by anthracyclines. This effect, which depends on luminal SR calcium concentration, is hypothesized to involve interactions of anthracyclines with the calcium binding protein calsequestrin (CSQ). This study was designed to test the hypothesis that an interaction between CSQ and anthracyclines could be related to alterations in SR calcium release and cardiac function. The effects of the anthracycline, daunorubicin, and its metabolite daunorubicinol were compared with those of a known CSQ inhibitor, trifluoperazine (TFP). Protein fluorescence quenching studies demonstrated that TFP, daunorubicin, and daunorubicinol bind to CSQ with apparent binding affinities in the low micromolar range. The presence of calcium decreases the drug-dependent fluorescence quenching, probably because of calcium-induced CSQ conformational changes. TFP also inhibited SR calcium release. Although the TFP IC50 value is somewhat larger than for anthracyclines, the TFP effect is also dependent on luminal SR calcium concentration. In a muscle preparation, micromolar TFP decreased cardiac contractility in a manner that implicates the involvement of SR calcium and resembles the effects of anthracyclines. These data are consistent with a mechanism in which TFP or anthracyclines impair SR calcium release and cardiac function through a mechanism involving disruption of CSQ function. Such a mechanism may contribute to anthracycline cardiotoxicity.


Asunto(s)
Calsecuestrina/metabolismo , Daunorrubicina/análogos & derivados , Daunorrubicina/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Trifluoperazina/administración & dosificación , Animales , Antraciclinas/administración & dosificación , Antraciclinas/química , Antraciclinas/metabolismo , Daunorrubicina/química , Daunorrubicina/metabolismo , Perros , Relación Dosis-Respuesta a Droga , Contracción Miocárdica/efectos de los fármacos , Contracción Miocárdica/fisiología , Conejos , Trifluoperazina/química , Trifluoperazina/metabolismo
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