1,417 research outputs found

    Utilization of a novel digital measurement tool for quantitative assessment of upper extremity motor dexterity: a controlled pilot study.

    Get PDF
    BackgroundThe current methods of assessing motor function rely primarily on the clinician's judgment of the patient's physical examination and the patient's self-administered surveys. Recently, computerized handgrip tools have been designed as an objective method to quantify upper-extremity motor function. This pilot study explores the use of the MediSens handgrip as a potential clinical tool for objectively assessing the motor function of the hand.MethodsEleven patients with cervical spondylotic myelopathy (CSM) were followed for three months. Eighteen age-matched healthy participants were followed for two months. The neuromotor function and the patient-perceived motor function of these patients were assessed with the MediSens device and the Oswestry Disability Index respectively. The MediSens device utilized a target tracking test to investigate the neuromotor capacity of the participants. The mean absolute error (MAE) between the target curve and the curve tracing achieved by the participants was used as the assessment metric. The patients' adjusted MediSens MAE scores were then compared to the controls. The CSM patients were further classified as either "functional" or "nonfunctional" in order to validate the system's responsiveness. Finally, the correlation between the MediSens MAE score and the ODI score was investigated.ResultsThe control participants had lower MediSens MAE scores of 8.09%±1.60%, while the cervical spinal disorder patients had greater MediSens MAE scores of 11.24%±6.29%. Following surgery, the functional CSM patients had an average MediSens MAE score of 7.13%±1.60%, while the nonfunctional CSM patients had an average score of 12.41%±6.32%. The MediSens MAE and the ODI scores showed a statistically significant correlation (r=-0.341, p<1.14×10⁻⁵). A Bland-Altman plot was then used to validate the agreement between the two scores. Furthermore, the percentage improvement of the the two scores after receiving the surgical intervention showed a significant correlation (r=-0.723, p<0.04).ConclusionsThe MediSens handgrip device is capable of identifying patients with impaired motor function of the hand. The MediSens handgrip scores correlate with the ODI scores and may serve as an objective alternative for assessing motor function of the hand

    Nucleon Magnetic Moments Beyond the Perturbative Chiral Regime

    Get PDF
    The quark mass dependence of nucleon magnetic moments is explored over a wide range. Quark masses currently accessible to lattice QCD, which lie beyond the regime of chiral perturbation theory (chiPT), are accessed via the cloudy bag model (CBM). The latter reproduces the leading nonanalytic behavior of chiPT, while modeling the internal structure of the hadron under investigation. We find that the predictions of the CBM are succinctly described by the simple formula, \mu_N(m_\pi) = \mu^{(0)}_N / (1 + \alpha m_\pi + \beta m_\pi^2), which reproduces the lattice data, as well as the leading nonanalytic behavior of chiPT. As this form also incorporates the anticipated Dirac moment behavior in the limit m_\pi \to \infty, it constitutes a powerful method for extrapolating lattice results to the physical mass regime.Comment: Revised version accepted for publication includes a new section demonstrating extrapolations of lattice QCD result

    Utilization of a novel digital measurement tool for quantitative assessment of upper extremity motor dexterity: a controlled pilot study

    Get PDF
    BACKGROUND: The current methods of assessing motor function rely primarily on the clinician’s judgment of the patient’s physical examination and the patient’s self-administered surveys. Recently, computerized handgrip tools have been designed as an objective method to quantify upper-extremity motor function. This pilot study explores the use of the MediSens handgrip as a potential clinical tool for objectively assessing the motor function of the hand. METHODS: Eleven patients with cervical spondylotic myelopathy (CSM) were followed for three months. Eighteen age-matched healthy participants were followed for two months. The neuromotor function and the patient-perceived motor function of these patients were assessed with the MediSens device and the Oswestry Disability Index respectively. The MediSens device utilized a target tracking test to investigate the neuromotor capacity of the participants. The mean absolute error (MAE) between the target curve and the curve tracing achieved by the participants was used as the assessment metric. The patients’ adjusted MediSens MAE scores were then compared to the controls. The CSM patients were further classified as either “functional” or “nonfunctional” in order to validate the system’s responsiveness. Finally, the correlation between the MediSens MAE score and the ODI score was investigated. RESULTS: The control participants had lower MediSens MAE scores of 8.09%±1.60%, while the cervical spinal disorder patients had greater MediSens MAE scores of 11.24%±6.29%. Following surgery, the functional CSM patients had an average MediSens MAE score of 7.13%±1.60%, while the nonfunctional CSM patients had an average score of 12.41%±6.32%. The MediSens MAE and the ODI scores showed a statistically significant correlation (r=-0.341, p<1.14×10(-5)). A Bland-Altman plot was then used to validate the agreement between the two scores. Furthermore, the percentage improvement of the the two scores after receiving the surgical intervention showed a significant correlation (r=-0.723, p<0.04). CONCLUSIONS: The MediSens handgrip device is capable of identifying patients with impaired motor function of the hand. The MediSens handgrip scores correlate with the ODI scores and may serve as an objective alternative for assessing motor function of the hand. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1743-0003-11-121) contains supplementary material, which is available to authorized users

    Genetically Encodable Contrast Agents for Optical Coherence Tomography

    Get PDF
    Optical coherence tomography (OCT) has gained wide adoption in biological research and medical imaging due to its exceptional tissue penetration, 3D imaging speed, and rich contrast. However, OCT plays a relatively small role in molecular and cellular imaging due to the lack of suitable biomolecular contrast agents. In particular, while the green fluorescent protein has provided revolutionary capabilities to fluorescence microscopy by connecting it to cellular functions such as gene expression, no equivalent reporter gene is currently available for OCT. Here, we introduce gas vesicles, a class of naturally evolved gas-filled protein nanostructures, as genetically encodable OCT contrast agents. The differential refractive index of their gas compartments relative to surrounding aqueous tissue and their nanoscale motion enables gas vesicles to be detected by static and dynamic OCT. Furthermore, the OCT contrast of gas vesicles can be selectively erased in situ with ultrasound, allowing unambiguous assignment of their location. In addition, gas vesicle clustering modulates their temporal signal, enabling the design of dynamic biosensors. We demonstrate the use of gas vesicles as reporter genes in bacterial colonies and as purified contrast agents in vivo in the mouse retina. Our results expand the utility of OCT to image a wider variety of cellular and molecular processes

    Genetically Encodable Contrast Agents for Optical Coherence Tomography

    Get PDF
    Optical coherence tomography (OCT) has gained wide adoption in biological research and medical imaging due to its exceptional tissue penetration, 3D imaging speed, and rich contrast. However, OCT plays a relatively small role in molecular and cellular imaging due to the lack of suitable biomolecular contrast agents. In particular, while the green fluorescent protein has provided revolutionary capabilities to fluorescence microscopy by connecting it to cellular functions such as gene expression, no equivalent reporter gene is currently available for OCT. Here, we introduce gas vesicles, a class of naturally evolved gas-filled protein nanostructures, as genetically encodable OCT contrast agents. The differential refractive index of their gas compartments relative to surrounding aqueous tissue and their nanoscale motion enables gas vesicles to be detected by static and dynamic OCT. Furthermore, the OCT contrast of gas vesicles can be selectively erased in situ with ultrasound, allowing unambiguous assignment of their location. In addition, gas vesicle clustering modulates their temporal signal, enabling the design of dynamic biosensors. We demonstrate the use of gas vesicles as reporter genes in bacterial colonies and as purified contrast agents in vivo in the mouse retina. Our results expand the utility of OCT to image a wider variety of cellular and molecular processes

    Baryon masses from lattice QCD: Beyond the perturbative chiral regime

    Get PDF
    Consideration of the analytic properties of pion-induced baryon self-energies leads to new functional forms for the extrapolation of light baryon masses. These functional forms reproduce the leading non-analytic behavior of chiral perturbation theory, the correct non-analytic behavior at the NπN \pi threshold and the appropriate heavy-quark limit. They involve only three unknown parameters, which may be obtained by fitting to lattice data. Recent dynamical fermion results from CP-PACS and UKQCD are extrapolated using these new functional forms. We also use these functions to probe the limit of applicability of chiral perturbation theory to the extrapolation of lattice QCD results.Derek B. Leinweber, Anthony W. Thomas, Kazuo Tsushima, and Stewart V. Wrigh

    Fisher Information as a Metric of Locally Optimal Processing and Stochastic Resonance

    Get PDF
    The origins of Fisher information are in its use as a performance measure for parametric estimation. We augment this and show that the Fisher information can characterize the performance in several other significant signal processing operations. For processing of a weak signal in additive white noise, we demonstrate that the Fisher information determines (i) the maximum output signal-to-noise ratio for a periodic signal; (ii) the optimum asymptotic efficacy for signal detection; (iii) the best cross-correlation coefficient for signal transmission; and (iv) the minimum mean square error of an unbiased estimator. This unifying picture, via inequalities on the Fisher information, is used to establish conditions where improvement by noise through stochastic resonance is feasible or not

    Citrobacter rodentium is an unstable pathogen showing evidence of significant genomic flux.

    Get PDF
    Citrobacter rodentium is a natural mouse pathogen that causes attaching and effacing (A/E) lesions. It shares a common virulence strategy with the clinically significant human A/E pathogens enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC) and is widely used to model this route of pathogenesis. We previously reported the complete genome sequence of C. rodentium ICC168, where we found that the genome displayed many characteristics of a newly evolved pathogen. In this study, through PFGE, sequencing of isolates showing variation, whole genome transcriptome analysis and examination of the mobile genetic elements, we found that, consistent with our previous hypothesis, the genome of C. rodentium is unstable as a result of repeat-mediated, large-scale genome recombination and because of active transposition of mobile genetic elements such as the prophages. We sequenced an additional C. rodentium strain, EX-33, to reveal that the reference strain ICC168 is representative of the species and that most of the inactivating mutations were common to both isolates and likely to have occurred early on in the evolution of this pathogen. We draw parallels with the evolution of other bacterial pathogens and conclude that C. rodentium is a recently evolved pathogen that may have emerged alongside the development of inbred mice as a model for human disease
    corecore