305 research outputs found
Towards MRI microarrays
Superparamagnetic iron oxide nanometre scale particles have been utilised as contrast agents to image staked target binding oligonucleotide arrays using MRI to correlate the signal intensity and relaxation times in different NMR fluids
A Theoretical Investigation of the Ground and LowâLying Excited States of Butadiene Radical Cation
Results are presented from ab initio calculations on the ground and several lowâlying excited states of the butadiene radical cation. In particular, we have calculated geometries for the ground and several excited states at the multiconfiguration selfâconsistent field level and characterized the planar stationary points. The vertical ionization potentials from the neutral molecule ground state and vertical excitation energies at the computed equilibrium geometry of the cation were also examined. A variety of methods were tested for the calculation of ionization potentials and excitation energies, including multiconfiguration selfâconsistent field, multireference singles and doubles configuration interaction (with and without sizeâconsistency correction), and multireference averaged coupled pair functional theory. It is found that several of the excited states are strong mixtures of soâcalled Koopmansâ and nonâKoopmansâ configurations. In most cases, good agreement is found with experiment, but the excitation energy for the second excited Ï state, a state which is multiconfigurational at zeroth order, is apparently overestimated at all levels of theory employed here
The Daughterless N-terminus directly mediates synergistic interactions with Notch transcription complexes via the SPS+A DNA transcription code
BACKGROUND: Cell-specific expression of a subset of Enhancer of split (E(spl)-C) genes in proneural clusters is mediated by synergistic interactions between bHLH A (basic Helix-Loop-Helix Activator) and Notch-signalling transcription complex (NTC) proteins. For a some of these E(spl)-C genes, such as m8, these synergistic interactions are programmed by an "SPS+A" transcription code in the cis-regulatory regions. However, the molecular mechanisms underlying this synergistic interaction between NTCs and proneural bHLH A proteins are not fully understood. FINDINGS: Using cell transcription assays, we show that the N-terminal region of the Daughterless (Da) bHLH A protein is critical for synergistic interactions with NTCs that activate the E(spl)-C m8 promoter. These assays also show that this interaction is dependent on the specific inverted repeat architecture of Suppressor of Hairless (Su(H)) binding sites in the SPS+A transcription code. Using protein-protein interaction assays, we show that two distinct regions within the Da N-terminus make a direct physical interaction with the NTC protein Su(H). Deletion of these interaction domains in Da creates a dominant negative protein that eliminates NTC-bHLH A transcriptional synergy on the m8 promoter. In addition, over-expression of this dominant negative Da protein disrupts Notch-mediated lateral inhibition during mechanosensory bristle neurogenesis in vivo. CONCLUSION: These findings indicate that direct physical interactions between Da-N and Su(H) are critical for the transcriptional synergy between NTC and bHLH A proteins on the m8 promoter. Our results also indicate that the orientation of the Su(H) binding sites in the SPS+A transcription code are critical for programming the interaction between Da-N and Su(H) proteins. Together, these findings provide insight into the molecular mechanisms by which the NTC synergistically interacts with bHLH A proteins to mediate Notch target gene expression in proneural clusters
Utilizing Mucosal Protrusion Angles to Discriminate Between True and False Masses of the Small Bowel on Video Capsule Endoscopy
Background: Video capsule endoscopy (VCE) has significantly improved our ability to detect small bowel tumors. However, diagnosing small bowel tumors has remained a challenge due to their low incidence, nonspecific presentations, and the inability to use VCE to biopsy lesions identified during passage through the small bowel. To address this challenge, Girelli et al. developed a novel scoring system called the âsmooth, protruding lesions index at capsule endoscopyâ (SPICE) to distinguish true submucosal masses from innocent bulges1. In our study, we compared the utility of an additional morphologic criterion, the mucosal protrusion angle, with SPICE scores in detecting true submucosal masses of the small-bowel.
Methods: We retrospectively reviewed the charts of 300 patients over the age of 18 who had undergone VCE for suspected small bowel lesions between the years of 2002 and 2017. In total, we analyzed the VCEs of 36 patients. SPICE scores were calculated for each patient as outlined in Girelli et al. and mucosal protrusion angles were measured using a protractor placed on the computer screen. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of both SPICE and protrusion angle. The protrusion angle was defined as the angle between the polyp and surrounding mucosa, and we hypothesized that an angle \u3e 900 suggested an external protrusion while an angle \u3c 900 suggested a submucosal mass or true polyp.
Results: 25 patients had true submucosal masses (2 GIST, 6 carcinoid, 5 Peutz-Jeghers, 3 inflammatory polyps, 2 hamartomatous polyps, 1 lymphoma, 1 lipomatous polyp, 2 tubular adenomas, 1 leiomyoma, 1 cavernous hemangioma, 1 hyperplastic polyp, 1 lymphatic nodule), and 10 patients had innocent bulges due to extrinsic compression. True submucosal masses when compared to innocent bulges had an average measured angle of protrusion of 45.70 ± 20.80 vs. 108.60 ± 16.30 (p \u3c 0.0001; unpaired t-test). When compared with SPICE scores, a mucosal protrusion angle \u3c 900 had a higher sensitivity (96.0% vs. 35.0%), specificity (90.0% vs. 82.0%), PPV (96.0% vs. 82.0%) and NPV (90.0% vs. 35.0%). Acute angle of protrusion accurately discriminated between true submucosal masses and extrinsic compression bulges on Fisherâs exact test (p = 0.0001).
Conclusion: Protrusion angle is a simple and useful tool for differentiating between true submucosal masses and innocent bulges of the small-bowel. Further prospective studies are needed to validate its utility in minimizing invasive interventions
Owner perceptions of their cat's quality of life when treated with a modified University of Wisconsin-Madison protocol for lymphoma
The objectives of this study were to assess owner perceptions of their catâs quality of life during treatment for lymphoma with a doxorubicin-containing multi-agent chemotherapy protocol, whether various health-related parameters correlated with quality of life scores, and to assess owner satisfaction with the protocol
Multistate Effects in Calculations of the Electronic Coupling Element for Electron Transfer Using the Generalized MullikenâHush Method
A simple diagnostic is developed for the purpose of determining when a third state must be considered to calculate the electronic coupling element for a given pair of diabatic states within the context of the generalized MullikenâHush approach (Chem. Phys. Lett. 1996, 275, 15â19). The diagnostic is formulated on the basis of Löwdin partitioning theory. In addition, an effective 2-state GMH expression is derived for the coupling as it is modified by the presence of the third state. Results are presented for (i) a model system involving charge transfer from ethylene to methaniminium cation, (ii) a pair of donorâacceptor-substituted acridinium ions, and (iii) (dimethylamino)benzonitrile, and the diagnostic is shown to be a useful indicator of the importance of multistate effects. The effective 2-state GMH expression is also shown to yield excellent agreement with the exact 3-state GMH results in most cases. For cases involving more than three interacting states a similar diagnostic is presented and several approximations to the full n-state GMH result are explored
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Why are âWhatâ and âWhereâ Processed by Separate Cortical Visual Systems? A Computational Investigation
In the primate visual system, the identification of objects and the processing of spatial information are accomplished by different cortical pathways. The computational properties of this âtwo-systemsâ design were explored by constructing simplifying connectionist models. The models were designed to simultaneously classify and locate shapes that could appear in multiple positions in a matrix, and the ease of forming representations of the two kinds of information was measured. Some networks were designed so that all hidden nodes projected to all output nodes, whereas others had the hidden nodes split into two groups, with some projecting to the output nodes that registered shape identity and the remainder projecting to the output nodes that registered location. The simulations revealed that splitting processing into separate streams for identifying and locating a shape led to better performance only under some circumstances. Provided that enough computational resources were available in both streams, split networks were able to develop more efficient internal representations, as revealed by detailed analyses of the patterns of weights between connections.Psycholog
An Immersive Motion Sketch Pad
GROCS: GRant Opportunities [collaborative spaces], a Digital Media Commons program to fund student research on the use of rich media in collaborative learning.http://deepblue.lib.umich.edu/bitstream/2027.42/57302/1/Cave_Capture proposal.pd
OPERATION OF CENTRIFUGAL COMPRESSORS IN CHOKE CONDITIONS
TutorialCentrifugal compressors are at times required to operate in or
near the choke region. Various limits of the degree of allowable
operation in choke have been established. Based on test data
and numerical data, the behavior of centrifugal compressors in
the choke region is studied. Changes in aerodynamic
performance, thrust load, volute behavior and radial loading are
considered. The issue of excitation of impeller vanes is
addressed. Particular consideration is given to multistage
machines, as well as dual compartment machines, in particular
regarding the effects of impeller mismatch during operating
conditions at flows significantly higher than the design flow.
Limitations in the overload operating range of a compressor not
only impact the operational flexibility , but also can require
more complicated control systems. The paper addresses
aerodynamic, structural as well as rotordynamic issues related
to the operation in choke
Call Me Caitlyn: Making and making over the 'authentic' transgender body in Anglo-American popular culture
A conception of transgender identity as an âauthenticâ gendered core âtrappedâ within a mismatched corporeality, and made tangible through corporeal transformations, has attained unprecedented legibility in contemporary Anglo-American media. Whilst pop-cultural articulations of this discourse have received some scholarly attention, the question of why this 'wrong body' paradigm has solidified as the normative explanation for gender transition within the popular media remains underexplored. This paper argues that this discourse has attained cultural pre-eminence through its convergence with a broader media and commercial zeitgeist, in which corporeal alteration and maintenance are perceived as means of accessing oneâs âauthenticâ self. I analyse the media representations of two transgender celebrities: Caitlyn Jenner and Nadia Almada, alongside the reality TV show TRANSform Me, exploring how these womenâs gender transitions have been discursively aligned with a cultural imperative for all women, cisgender or trans, to display their authentic femininity through bodily work. This demonstrates how established tropes of authenticity-via-bodily transformation, have enabled transgender to become culturally legible through the wrong body trope. Problematically, I argue, this process has worked to demarcate ideals of âacceptableâ transgender subjectivity: self-sufficient, normatively feminine, and eager to embrace the possibilities for happiness and social integration provided by the commercial domain
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