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High Fidelity (high + fidelity)
Selected AbstractsMaximum likelihood constrained deconvolution.CONCEPTS IN MAGNETIC RESONANCE, Issue 2 2003II: Application to experimental two-, three-dimensional NMR spectra Abstract The maximum likelihood method (MLM) and related protocols were applied to the experimental 2-D nuclear Overhauser effect (NOE) spectrum of a 24-nucleotide RNA hairpin loop molecule. The output becomes more valuable when diagonal symmeterization is followed by MLM. This symmeterized maximum likelihood (SML) protocol restores the original spectral information with high fidelity by accurately partitioning components from overlapped peaks and provides substantial improvements in line shape and spectral resolution, in particular in the F1 dimension. These advantages lead to a simpler interpretation of the resonance frequencies, intensities, multiplet fine structure, and J -coupling values from a heavily overlapped peak region. This promises a more effective tool for peak picking, assignment, and integration. Also, application of MLM and related protocols to the 2-D NOE proton spectrum of a 24-mer RNA dramatically increases the number of NOE-based distance constraints that can be used for determination of its 3-D molecular structure. By application of 3-D MLM to a simple 3-D spectrum, the spectral resolution and signal-to-noise (S/N) ratio was greatly improved by effective line sharpening and reduction of cross-talk between planes. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson 18A: 146,156, 2003 [source] Simulation-based Morbidity and Mortality Conference: New Technologies Augmenting Traditional Case-based PresentationsACADEMIC EMERGENCY MEDICINE, Issue 1 2006John Vozenilek MD Abstract The authors describe the use of a high-fidelity simulation laboratory to re-create a patient encounter for the purposes of enhancing a morbidity and mortality conference. The use of two separate technologies were enlisted: a METI high-fidelity patient simulator to re-create the case in a more lifelike fashion, and an audience response system to collect clinical impressions throughout the case presentation and survey data at the end of the presentation. The re-creation of the patient encounter with all relevant physical findings displayed in high fidelity, with relevant laboratory data, nursing notes, and imaging as it occurred in the actual case, provides a more engaging format for the resident,learner. This technological enhancement was deployed at a morbidity and mortality conference, and the authors report the impressions collected via the audience response system. Guidelines for those who wish to re-create this type of educational experience are presented in the discussion. [source] Evaluation of Left Ventricular Systolic and Diastolic Global Function: Peak Positive and Negative Myocardial Velocity Gradients in M-Mode Doppler Tissue ImagingECHOCARDIOGRAPHY, Issue 1 2002Yoshiki Ueno M.D. Objectives: To evaluate a new indicator of left ventricular global function: Myocardial velocity gradient (MVG) M-mode Doppler tissue imaging (DTI). Background: MVG is a new indicator of regional left ventricular function and global left ventricular diastolic function. However, it is unclear whether MVG also is an indicator of left ventricular global function in comparison with invasive indices. Methods: We performed conventional imaging and M-mode DTI in 85 subjects and calculated MVG at the posterior wall. We obtained satisfactory images in 65 subjects, who we divided into three groups: Noninvasive study group, invasive study group, and hemodialysis group. The noninvasive study group was divided into three subgroups (a younger normal subgroup, an older normal subgroup, and a cardiomyopathy subgroup), and MVG was compared with indices of conventional imaging. In the invasive study group, we compared MVG and indices of conventional imaging with hemodynamic data (peak positive and negative dp/dt, and the time constant T) using a high fidelity micromanometer-tipped catheter. In the hemodialysis group, we compared indices before hemodialysis with those after hemodialysis. Results: Peak positive MVG correlated well with peak positive dp/dt (r = 0.79), and this did not change with hemodialysis (P = 0.87). Peak negative MVG also correlated well with peak positive dp/dt and the time constant T (r = 0.88 and r = 0.80), and this did not change with hemodialysis (P = 0.97). Conclusions: Peak positive and negative MVG are sensitive and load-insensitive indicators of left ventricular function. [source] Just how does the cII selection system work in MutaÔMouse?ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2001Roy R. Swiger Abstract The lambda CII protein is an essential component in the lytic vs. lysogeny decision a bacteriophage makes upon infection of a host at low temperatures. The protein interacts with numerous phage promoters modulating the expression of the CI repressor, thus providing the mechanism for lysogenization soon after infection. The Big Blue® and MutaÔMouse are two widely used in vivo mutational model systems. The assays rely on retrievable lambda-based transgenes housing mutational targets (lacI or lacZ, respectively). The transgenes provide an elegant vehicle for the quantification of mutations sustained in virtually any tissue of the rodent. The use of the bacteriophage cII locus as an alternative, or additional mutational target for use with the Big Blue® rodent system was first reported by Jakubczak et al. ([1996]: Proc Natl Acad Sci USA 93:9073,9078). More recently, this selection assay has been applied successfully to the MutaÔMouse (Swiger et al. [1999]: Environ Mol Mutagen 33:201,207). The use of an Hfl bacterial strain and low temperature allows the determination of mutations sustained at the cII locus in either system, with high fidelity. The cII selection assay in the Big Blue® relies on the presence of the lambda repressor protein CI. In contrast, the recombinant construct used to make the MutaÔMouse transgene lacks functional CI protein. Nevertheless, we report an excellent system for quantifying mutations at the cII locus in MutaÔMouse. Just how does cII selection work in the MutaÔMouse? Written in the context of lambda recombinant genetics, this paper explores the question further. Environ. Mol. Mutagen. 37:290,296, 2001 © 2001 Wiley-Liss, Inc. [source] Characterization of HLA DR3/DQ2 transgenic mice: a potential humanized animal model for autoimmune disease studiesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 1 2003Dan Chen Abstract Linkage studies indicate close associations of certain HLA alleles with autoimmune diseases. To better understand how specific HLA alleles are related to disease pathogenesis, we have generated an HLA DR3/DQ2 transgenic mouse utilizing a 550-kb yeast artificial chromosome (YAC) construct containing the complete DR,, DR,1, DR,3, DQ,, and DQ, regions. The transgenic mouse (4D1/C2D) in an I-A,o background appears healthy with no signs of autoimmune diseases. Lymphoid tissues as well as CD4+ T cells develop normally. Characterization of the transgene expression demonstrates that ,90% of B cells express high levels of DR3 and 50,70% of B cells express DQ2. CD11c+ dendritic cells express high levels of DR and DQ. Approximately12,18% of resting T cells are positive for DR expression, and further up-regulation to 40,50% expression is seen upon activation with anti-CD3/anti-CD28 mAb. These results suggest that the transgenic construct confers a high fidelity to the normal human temporal and spatial expression profile. Analysis of T cell receptor repertoire in transgenic mice confirms that DR3/DQ2 are able to mediate thymic selection. Furthermore, transgenic mice respond to a DR3-restricted antigen, demonstrating antigen processing and presentation by antigen-presenting cells (APC). Purified T cells from ovalbumin (OVA)-immunized 4D1 mice respond to human APC co-cultured with OVA, suggesting appropriate antigen/DR3 or DQ2 recognition by murine T cells. Immunoglobulin isotype switching is also observed, indicating functional T-B cognate interactions. Thus, the DR3/DQ2 transgenic mouse has normal lymphoid development and functionality that are mediated by HLA transgenes and can be used to investigate HLA-associated immunological questions. [source] Mechanical Gradient Cues for Guided Cell Motility and Control of Cell Behavior on Uniform SubstratesADVANCED FUNCTIONAL MATERIALS, Issue 18 2009Barbara Cortese Abstract A novel method for the fabrication and the use of simple uniform poly(dimethylsiloxane) PDMS substrates for controlling cell motility by a mechanical gradient is reported. The substrate is fabricated in PDMS using soft lithography and consists of a soft membrane suspended on top of a patterned PDMS substrate. The difference in the gradient stiffness is related to the underlying pattern. It is shown experimentally that these uniform substrates can modulate the response of cell motility, thus enabling patterning on the surfaces with precise cell motility. Because of the uniformity of the substrate, cells can spread equally and a directional movement to stiffer regions is clearly observed. Varying the geometry underlying the membrane, cell patterning and movement can be quantitatively characterized. This procedure is capable of controlling cell motility with high fidelity over large substrate areas. The most significant advance embodied in this method is that it offers the use of mechanical features to control cell adhesion and not topographical or chemical variations, which has not been reported so far. This modulation of the response of cell motility will be useful for the design and fabrication of advanced planar and 3D biological assemblies suitable for applications in the field of biotechnology and for tissue-engineering purposes. [source] Developmental control via GATA factor interplay at chromatin domainsJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2005Emery H. Bresnick Despite the extraordinary task of packaging mammalian DNA within the constraints of a cell nucleus, individual genes assemble into cell type-specific chromatin structures with high fidelity. This chromatin architecture is a crucial determinant of gene expression signatures that distinguish specific cell types. Whereas extensive progress has been made on defining biochemical and molecular mechanisms of chromatin modification and remodeling, many questions remain unanswered about how cell type-specific chromatin domains assemble and are regulated. This mini-review will discuss emerging studies on how interplay among members of the GATA family of transcription factors establishes and regulates chromatin domains. Dissecting mechanisms underlying the function of hematopoietic GATA factors has revealed fundamental insights into the control of blood cell development from hematopoietic stem cells and the etiology of pathological states in which hematopoiesis is perturbed. © 2005 Wiley-Liss, Inc. [source] Testing the Long-Term Effects of the Go Sun Smart Worksite Health Communication Campaign: A Group-Randomized Experimental StudyJOURNAL OF COMMUNICATION, Issue 3 2008Peter A. Andersen This study examined the long-term effects of the Go Sun Smart (GSS) campaign, a large-scale health communication intervention designed to promote sun safety to employees at 26 ski areas in western North America. Employees were enrolled in a pair-matched group-randomized pretest,posttest controlled design with 2 follow-up surveys. Half of the ski areas were randomly assigned to implement GSS in the winter. This article reports analyses of a hierarchical linear design with responses from 1,463 employees who completed the second follow-up survey at the end of the following summer (69% of those who completed the first posttest). GSS continued to have positive effects on employees who worked at intervention ski areas into the summer. Employees exposed to GSS reported less sunburning, engaged in more sun safety behaviors, were more aware of the program, and had more discussions of sun safety at home than employees at matched control group resorts. The long-term effects of GSS support recommending that sun protection programs be implemented at workplaces, but such programs should be implemented with high fidelity to achieve maximum benefits. Despite limitations due to nonresponse, geography, measurement, and ethnicity, the hierarchical clustered design improved the internal validity and generalizability of the findings. [source] Fabrication of Artificial Petal Sculptures by Replication of Sub-micron Surface Wrinkles,MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 2 2010Alexandra Schweikart Abstract In this contribution, we discuss wrinkling as a process resulting in well-defined periodic micron-sized structures, as known from the interface of several plant cells. We show possible pathways to transfer this principle to artificial materials such as epoxy resins or polymers. While topographical structuring of surfaces by wrinkling is meanwhile well established for elastomers like poly (dimethyl siloxane), so far the step towards other classes of materials has not been taken. This puts several limitations to potential applications of artificial wrinkled structures, as elastomers show poor dimensional stability, low optical quality, and tend to swell in organic solvents. As well, artificial structures formed by wrinkling are not tension-free on the microscopic level, which makes them metastable. Residual mechanical tensions can affect dimensional stability on long timescales. We introduce two processes, micro thermoforming and molding, as means to overcome these restrictions and to pattern non-elastomeric materials by using wrinkled elastomers as templates. The two approaches allow the formation of negative and positive replicas and allow the transfer of sub-micron features with high fidelity. [source] Incongruent patterns of genetic connectivity among four ophiuroid species with differing coral host specificity on North Atlantic seamountsMARINE ECOLOGY, Issue 2010Walter Cho Abstract Seamounts are considered to play a defining role in the evolution and diversity of marine fauna, acting as ,stepping-stones' for dispersal, regional centers of genetic isolation and speciation, and refugia for deep-sea populations. This study focused on the patterns of dispersal and genetic connectivity of four seamount ophiuroid species (Asteroschema clavigera, Ophiocreas oedipus, Ophioplinthaca abyssalis, and Ophioplinthaca chelys) displaying differing levels of associative (epifaunal) specificity to cold-water coral hosts inhabiting the New England and Corner Rise Seamount chains, and Muir Seamount in the Northwestern Atlantic. Analyses of mt16S and mtCOI revealed evidence for recent population expansion and high gene flow for all four species. However, species-specific genetic differentiation was significant based on seamount region and depth. Significant differences were found among regional seamount groups for A. clavigera, within seamount regions and seamounts for O. chelys, among 250-m depth intervals for A. clavigera, among 100-m depth intervals for O. oedipus, and there were indications of isolation by distance for A. clavigera and O. oedipus. In addition, A. clavigera and O. oedipus, broadcast spawners with high fidelity to specific coral hosts, displayed predominantly westward historical migration, whereas the ophioplinthacids, with lower host-specificity, displayed predominantly eastward migration. No congruent patterns of historical migration were evident among species and seamounts, yet these patterns can be correlated with species-specific host specificity, specific depth strata, and dispersal strategies. Conservation efforts to protect seamount ecosystems should promote multi-species approaches to genetic connectivity, and consider the impact of the ,dependence' of biodiversity on host fauna in these vulnerable marine ecosystems. [source] Application of ground-penetrating radar imagery for three-dimensional visualisation of near-surface structures in ice-rich permafrost, Barrow, AlaskaPERMAFROST AND PERIGLACIAL PROCESSES, Issue 4 2007Jeffrey S. Munroe Abstract Three-dimensional ground-penetrating radar (3D GPR) was used to investigate the subsurface structure of ice-wedge polygons and other features of the frozen active layer and near-surface permafrost near Barrow, Alaska. Surveys were conducted at three sites located on landscapes of different geomorphic age. At each site, sediment cores were collected and characterised to aid interpretation of GPR data. At two sites, 3D GPR was able to delineate subsurface ice-wedge networks with high fidelity. Three-dimensional GPR data also revealed a fundamental difference in ice-wedge morphology between these two sites that is consistent with differences in landscape age. At a third site, the combination of two-dimensional and 3D GPR revealed the location of an active frost boil with ataxitic cryostructure. When supplemented by analysis of soil cores, 3D GPR offers considerable potential for imaging, interpreting and 3D mapping of near-surface soil and ice structures in permafrost environments. Copyright © 2007 John Wiley & Sons, Ltd. [source] Photolysis of Br2 in CCl4 studied by time-resolved X-ray scatteringACTA CRYSTALLOGRAPHICA SECTION A, Issue 2 2010Qingyu Kong A time-resolved X-ray solution scattering study of bromine molecules in CCl4 is presented as an example of how to track atomic motions in a simple chemical reaction. The structures of the photoproducts are tracked during the recombination process, geminate and non-geminate, from 100,ps to 10,µs after dissociation. The relaxation of hot Br2* molecules heats the solvent. At early times, from 0.1 to 10,ns, an adiabatic temperature rise is observed, which leads to a pressure gradient that forces the sample to expand. The expansion starts after about 10,ns with the laser beam sizes used here. When thermal artefacts are removed by suitable scaling of the transient solvent response, the excited-state solute structures can be obtained with high fidelity. The analysis shows that 30% of Br2* molecules recombine directly along the X potential, 60% are trapped in the A/A, state with a lifetime of 5.5,ns, and 10% recombine non-geminately via diffusive motion in about 25,ns. The Br,Br distance distribution in the A/A, state peaks at 3.0,Å. [source] Surface-directed assembly of cell-laden microgels,,BIOTECHNOLOGY & BIOENGINEERING, Issue 3 2010Yanan Du Abstract Cell-laden microscale hydrogels (microgels) can be used as tissue building blocks and assembled to create 3D tissue constructs with well-defined microarchitecture. In this article, we present a bottom-up approach to achieve microgel assembly on a patterned surface. Driven by surface tension, the hydrophilic microgels can be assembled into well-defined shapes on a glass surface patterned with hydrophobic and hydrophilic regions. We found that the cuboidic microgels (,100,200,µm in width) could self-assemble into defined shapes with high fidelity to the surface patterns. The microgel assembly process was improved by increasing the hydrophilicity of the microgels and reducing the surface tension of the surrounding solution. The assembled microgels were stabilized by a secondary crosslinking step. Assembled microgels containing cells stained with different dyes were fabricated to demonstrate the application of this approach for engineering microscale tissue constructs containing multiple cell types. This bottom-up approach enables rapid fabrication of cell-laden microgel assemblies with pre-defined geometrical and biological features, which is easily scalable and can be potentially used in microscale tissue engineering applications. Biotechnol. Bioeng. 2010; 105: 655,662. © 2009 Wiley Periodicals, Inc. [source] De novo synthesis and assembly of multiplex riboswitches in vitroBIOTECHNOLOGY PROGRESS, Issue 5 2009Hao-Hua Sun Abstract Pools of short synthetic oligonucleotides (oligos) are required in the multiplex and parallel DNA construction. Microarray technology provides a fast and economical mean for massive parallel synthesis of oligos. The method of oligo synthesis with the programmable microfluidic PicoArray could simultaneously synthesize the designed oligos for multiple riboswitch genes. The synthetic oligos were recovered and purified as a pool of oligo mixture (OligoMix). Three temperature steps were employed to denature, anneal and extend the designed OligoMix until, after multiple rounds of thermocycling, the riboswitches with the desired length are obtained. The OligoMix was amplified using this PCR-based technique and the flanking adapter segments were cleaved for following assembly. Based on these oligos derived from 197 riboswitch sequences, the method of simultaneous assembling multiplex riboswitches (SAMRs) showed high fidelity by sequence identification. The resultant error rate was determined to be 2.78,. With the templates from SAMRs, in vitro transcription was applied to produce milligram amounts of biologically active riboswitches. With the verification of biological activity based on the high specificity of recognizing small-molecule metabolites as well as the DNA sequence redivivus by RT-PCR, the assembled riboswitches can be used for further gene operation and biological application. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Service delivery in older patients with bipolar disorder: a review and development of a medical care modelBIPOLAR DISORDERS, Issue 6 2008Amy M Kilbourne Objectives:, Medical comorbidities, especially cardiovascular disease (CVD), occur disproportionately in older patients with bipolar disorder. We describe the development, implementation, and feasibility/tolerability results of a manual-based medical care model (BCM) designed to improve medical outcomes in older patients with bipolar disorder. Methods:, The BCM consisted of (i) self-management sessions focused on bipolar disorder symptom control, healthy habits, and provider engagement, (ii) telephone care management to coordinate care and reinforce self-management goals, and (iii) guideline dissemination focused on medical issues in bipolar disorder. Older patients with bipolar disorder and a CVD-related risk factor (n = 58) were consented, enrolled, and randomized to receive BCM or usual care. Results:, Baseline assessment (mean age = 55, 9% female, 9% African American) revealed a vulnerable population: 21% were substance users, 31% relied on public transportation, and 22% reported problems accessing medical care. Evaluation of BCM feasibility revealed high overall patient satisfaction with the intervention, high fidelity (e.g., majority of self-management sessions and follow-up contacts completed), and good tolerability (dropout rate <5%). Use of telephone contacts may have mitigated barriers to medical care (e.g., transportation). Conclusions:, The BCM is a feasible model for older, medically ill patients with bipolar disorder, and could be an alternative to more costly treatment models that involve co-location and/or additional hiring of medical providers in mental health clinics. Future research directions pertinent to the development of the BCM and other medical care models for older patients with bipolar disorder include assessment of their long-term effects on physical health and their cost-effectiveness across different treatment settings. [source] Recolouring digital textile printing design with high fidelityCOLORATION TECHNOLOGY, Issue 1 2004J H Xin An algorithm of recolouring of polychromatic digital textile printing images is proposed based on the investigation of texture and colour distribution in different channels and image segmentation. A polychromatic image is first separated into monochromatic regions based on watershed transformation in CIELAB colour space. The initial markers are selected by hierarchical histogram analysis to eliminate the inherent drawbacks of over-segmentation in the watershed algorithm. Then the individual monochromatic regions can be mapped with different colours to obtain desirable designs. The artefacts in the boundaries of different regions are reduced by a technique of colour mixing through Gaussian blurring. The experimental simulation results indicated that the performance of the algorithm was quite good in both texture and colour fidelity. [source] | ||||||||||||||||||||||