The Impact of the Lead Teacher Professional Learning Community within the Rice University Mathematics Leadership Institute

Now in its fourth year, Rice University’s Mathematics Leadership Institute (MLI) has developed over sixty high school mathematics Lead Teachers. We focus on how membership in MLI has impacted participant teachers’ professional lives. The Lead Teacher community that emerged during MLl’s first Summer Leadership Institute embodies the characteristics of a sustaining and coherent knowledge community where teachers are able to share their secret “stories of practice in safe places . . . in order to make their personal practical knowledge explicit to themselves and to others” [1]. This article includes stories of individual teachers who refused to sacrifice hours of instructional time for mandated curriculum testing, who encouraged and supported a large group of MLI teachers to participate in a grueling advanced certification program, and who challenged the local administration’s expectation to compromise personal professional standards. These stories may not have emerged in their particular ways had these teachers and their supporting co-manager not been members of this coherent and sustained knowledge community. This knowledge community has enabled the achievement of MLI goals with respect to teachers’ increased mathematics content knowledge, leadership development, and student achievement. We also include focus group comments and quantitative data

The energy substrate switch during cardiac development, with the onset of cardiac hypertrophy and the transition to heart failure. : delineation and characterisation of gene regulatory mechanisms : "changing concepts of metabolic regulation in the h

Bibliography: leaves 168-190

Simulating local deformations in the human cortex due to blood flow-induced changes in mechanical tissue properties: Impact on functional magnetic resonance imaging

Investigating human brain tissue is challenging due to the complexity and the manifold interactions between structures across different scales. Increasing evidence suggests that brain function and microstructural features including biomechanical features are related. More importantly, the relationship between tissue mechanics and its influence on brain imaging results remains poorly understood. As an important example, the study of the brain tissue response to blood flow could have important theoretical and experimental consequences for functional magnetic resonance imaging (fMRI) at high spatial resolutions. Computational simulations, using realistic mechanical models can predict and characterize the brain tissue behavior and give us insights into the consequent potential biases or limitations of in vivo, high-resolution fMRI. In this manuscript, we used a two dimensional biomechanical simulation of an exemplary human gyrus to investigate the relationship between mechanical tissue properties and the respective changes induced by focal blood flow changes. The model is based on the changes in the brain’s stiffness and volume due to the vasodilation evoked by neural activity. Modeling an exemplary gyrus from a brain atlas we assessed the influence of different potential mechanisms: (i) a local increase in tissue stiffness (at the level of a single anatomical layer), (ii) an increase in local volume, and (iii) a combination of both effects. Our simulation results showed considerable tissue displacement because of these temporary changes in mechanical properties. We found that the local volume increase causes more deformation and consequently higher displacement of the gyrus. These displacements introduced considerable artifacts in our simulated fMRI measurements. Our results underline the necessity to consider and characterize the tissue displacement which could be responsible for fMRI artifacts

Movers and shakers: Granular damping in microgravity

The response of an oscillating granular damper to an initial perturbation is studied using experiments performed in microgravity and granular dynamics mulations. High-speed video and image processing techniques are used to extract experimental data. An inelastic hard sphere model is developed to perform simulations and the results are in excellent agreement with the experiments. The granular damper behaves like a frictional damper and a linear decay of the amplitude is bserved. This is true even for the simulation model, where friction forces are absent. A simple expression is developed which predicts the optimal damping conditions for a given amplitude and is independent of the oscillation frequency and particle inelasticities.Comment: 9 pages, 9 figure

Delta opioid receptor stimulation mimics ischemic preconditioning in human heart muscle

AbstractOBJECTIVESThe objective of this study was to examine whether the delta (δ) opioid receptor isoform is expressed in the human heart and whether this receptor improves contractile function after hypoxic/reoxygenation injury.BACKGROUNDDelta opioid receptor agonists mimic preconditioning (PC) in rat myocardium, corresponding to known cardiac δ opioid receptor expression in this species.METHODSThe messenger RNA transcript encoding the δ opioid receptor was identified in human atria and ventricles. To evaluate the cardioprotective role of the opioid receptor, human atrial trabeculae from patients undergoing coronary bypass grafting were isolated and superfused with Tyrode’s solution. A control group underwent 90 min of simulated ischemia and 120 min of reoxygenation. A second group was preconditioned with 3 min simulated ischemia and 7 min reoxygenation. Additional groups included: superfusion with the δ receptor agonist (DADLE) (10 nM), with the δ receptor antagonist naltrindole (10 nM) and with the mitochondrial KATP channel blocker 5-hydroxydecanoate (5HD) (100 μM) either with or without PC, respectively. A final group was superfused with 5HD before DADLE. The end point used was percentage of developed force after 120 min of reoxygenation.RESULTSResults, expressed as means ± SEM, were: control = 32.6 ± 3.8%; PC = 50.5% ± 1.8∗; DADLE = 46.0 ± 3.9%∗; PC + naltrindole = 25.5 ± 3.9%; naltrindole alone = 25.5 ± 4.3%; 5HD + PC = 28.9 ± 7.4%; 5HD alone = 24.1 ± 3.0%; 5HD + DADLE = 26.9 ± 4.4% (∗p < 0.001 vs. controls).CONCLUSIONSHuman myocardium expresses the δ opioid receptor transcript. Stimulation of this receptor appears to protects human muscle from simulated ischemia, similar to PC, and via opening of the mitochondrial KATP channel

Biodigital publics: personal genomes as digital media artifacts

The recent proliferation of personal genomics and direct-to-consumer (DTC) genomics has attracted much attention and publicity. Concern around these developments has mainly focused on issues of biomedical regulation and hinged on questions of how people understand genomic information as biomedical and what meaning they make of it. However, this publicity amplifies genome sequences which are also made as internet texts and, as such, they generate new reading publics. The practices around the generation, circulation and reading of genome scans do not just raise questions about biomedical regulation, they also provide the focus for an exploration of how contemporary public participation in genomics works. These issues around the public features of DTC genomic testing can be pursued through a close examination of the modes of one of the best known providers—23andMe. In fact, genome sequences circulate as digital artefacts and, hence, people are addressed by them. They are read as texts, annotated and written about in browsers, blogs and wikis. This activity also yields content for media coverage which addresses an indefinite public in line with Michael Warner’s conceptualisation of publics. Digital genomic texts promise empowerment, personalisation and community, but this promise may obscure the compliance and proscription associated with these forms. The kinds of interaction here can be compared to those analysed by Andrew Barry. Direct-to-consumer genetics companies are part of a network providing an infrastructure for genomic reading publics and this network can be mapped and examined to demonstrate the ways in which this formation both exacerbates inequalities and offers possibilities for participation in biodigital culture

Individual-specific changes in the human gut microbiota after challenge with enterotoxigenic Escherichia coli and subsequent ciprofloxacin treatment

Acknowledgements The authors wish to thank Mark Stares, Richard Rance, and other members of the Wellcome Trust Sanger Institute’s 454 sequencing team for generating the 16S rRNA gene data. Lili Fox Vélez provided editorial support. Funding IA, JNP, and MP were partly supported by the NIH, grants R01-AI-100947 to MP, and R21-GM-107683 to Matthias Chung, subcontract to MP. JNP was partly supported by an NSF graduate fellowship number DGE750616. IA, JNP, BRL, OCS and MP were supported in part by the Bill and Melinda Gates Foundation, award number 42917 to OCS. JP and AWW received core funding support from The Wellcome Trust (grant number 098051). AWW, and the Rowett Institute of Nutrition and Health, University of Aberdeen, receive core funding support from the Scottish Government Rural and Environmental Science and Analysis Service (RESAS).Peer reviewedPublisher PD