772 research outputs found
Design and evaluation of a digital processing unit for satellite angular velocity estimation
A satellite's absolute attitude and angular rate are both important measurements for satellite missions that require navigation. Typically, these measurements have been made by separate sensors, with star cameras being used to determine a satellite's absolute attitude, and gyroscopes being used as the primary rate sensors. Recently, there have been multiple efforts to measure both of these quantities using only the star camera, however the work primarily involves solutions where the optical sensor and the unit that processes the images are separate integrated circuits. Operation in this modality requires the use of chip to chip communication in order to estimate angular rate from star tracker images, which can lead to an increase in system power, a degradation in performance, and increased latency. The goal of this thesis is to consolidate the sensing and processing into a single integrated circuit. The design and evaluation of a digital processing unit that estimates angular rate and facilitates the realization of image sensor and processor integration is presented. The processing unit is implemented in UMC's 130 nm process, has an area of 10 mm Ć 200 Ī¼m, and consumes 8.253 mW of power
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Meta-analysis of the Cepheid XpertĀ® CT/NG assay for extragenital detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections.
Background Most studies evaluating extragenital testing performance for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) detection by the XpertĀ® CT/NG show high per cent agreement with comparison assays; however, the precision around positive per cent agreement is low and thus the values that have been reported are not highly informative. Therefore, a systematic review was conducted and data from five studies were combined to better assess positive per cent agreement.MethodsThe literature indexed on PubMed.gov was searched. Included studies were those that were an evaluation of the Xpert CT/NG assay with rectal and/or pharyngeal specimen types compared with another nucleic acid amplification test (NAAT), the Aptima transcription mediated amplification assay. A full Bayesian method was used for bivariate fixed-effect meta-analysis of positive and negative per cent agreement and pooled estimates (and 95% confidence intervals (CI)) were presented for each.ResultsThe pooled positive and negative per cent agreement for detection of CT in rectal specimens was 89.72% (95% CI: 84.97%, 93.64%) and 99.23% (95% CI: 98.74%, 99.60%), and in pharyngeal specimens, they were 89.96% (95% CI: 66.38%, 99.72%) and 99.62% (95% CI: 98.95%, 99.95%) respectively. For NG detection in rectal specimens, the pooled positive and negative per cent agreement was 92.75% (95% CI: 87.91%, 96.46%) and 99.75% (95% CI: 99.46%, 99.93%), and in pharyngeal specimens, they were 92.51% (95% CI: 85.84%, 97.18%) and 98.56% (95% CI: 97.69%, 99.23%) respectively.ConclusionsIt was found that the Xpert CT/NG assay performed similarly to the Aptima transcription mediated amplification assay for the detection of CT and NG in extragenital specimens. The Xpert assay has the benefit of providing faster results at the point-of-care, thus reducing the turnaround time for results, potentially enabling same-day treatment
Local environmental and meteorological conditions influencing the invasive mosquito Ae. albopictus and arbovirus transmission risk in New York City
Ae. albopictus, an invasive mosquito vector now endemic to much of the northeastern US, is a significant public health threat both as a nuisance biter and vector of disease (e.g. chikungunya virus). Here, we aim to quantify the relationships between local environmental and meteorological conditions and the abundance of Ae. albopictus mosquitoes in New York City. Using statistical modeling, we create a fine-scale spatially explicit risk map of Ae. albopictus abundance and validate the accuracy of spatiotemporal model predictions using observational data from 2016. We find that the spatial variability of annual Ae. albopictus abundance is greater than its temporal variability in New York City but that both local environmental and meteorological conditions are associated with Ae. albopictus numbers. Specifically, key land use characteristics, including open spaces, residential areas, and vacant lots, and spring and early summer meteorological conditions are associated with annual Ae. albopictus abundance. In addition, we investigate the distribution of imported chikungunya cases during 2014 and use these data to delineate areas with the highest rates of arboviral importation. We show that the spatial distribution of imported arboviral cases has been mostly discordant with mosquito production and thus, to date, has provided a check on local arboviral transmission in New York City. We do, however, find concordant areas where high Ae. albopictus abundance and chikungunya importation co-occur. Public health and vector control officials should prioritize control efforts to these areas and thus more cost effectively reduce the risk of local arboviral transmission. The methods applied here can be used to monitor and identify areas of risk for other imported vector-borne diseases
Analysis of wave III of brain stem auditory evoked potential waveforms during microvascular decompression of cranial nerve VII for hemifacial spasm
INTRODUCTION:: Intraoperative monitoring of brain stem auditory evoked potential during microvascular decompression (MVD) prevent hearing loss (HL). Previous studies have shown that changes in wave III (wIII) are an early and sensitive sign of auditory nerve injury. OBJECTIVE:: To evaluate the changes of amplitude and latency of wIII of brain stem auditory evoked potential during MVD and its association with postoperative HL. Hearing loss was classified by American Academy of Otolaryngology - Head and Neck Surgery (AAO-HNS) criteria, based on changes in pure tone audiometry and speech discrimination score. METHODS:: Retrospective analysis of wIII in patients who underwent intraoperative monitoring with brain stem auditory evoked potential during MVD was performed. A univariate logistic regression analysis was performed on independent variables amplitude of wIII and latency of wIII at change max and On-Skin, or a final recording at the time of skin closure. A further analysis for the same variables was performed adjusting for the loss of wave. RESULTS:: The latency of wIII was not found to be significantly different between groups I and II. The amplitude of wIII was significantly decreased in the group with HL. Regression analysis did not find any increased odds of HL with changes in the amplitude of wIII. CONCLUSIONS:: Changes in wave III did not increase the odds of HL in patients who underwent brain stem auditory evoked potential s during MVD. This information might be valuable to evaluate the value of wIII as an alarm criterion during MVD to prevent HL. Ā© 2014 by the American Clinical Neurophysiology Society
Acute carpal tunnel syndrome: early nerve decompression and surgical stabilization for bony wrist trauma
Background We undertook this study to investigate the outcomes of surgical treatment for acute carpal tunnel syndrome following our protocol for concurrent nerve decompression and skeletal stabilization for bony wrist trauma to be undertaken within 48-hours. Methods We identified all patients treated at our trauma centre following this protocol between 1 January 2014 and 31 December 2019. All patients were clinically reviewed at least 12 months following surgery and assessed using the Brief Michigan Hand Outcomes Questionnaire (bMHQ), the Boston Carpal Tunnel Questionnaire (BCTQ) and sensory assessment with Semmes-Weinstein monofilament testing. Results The study group was made up of 35 patients. Thirty-three patients were treated within 36-hours. Patients treated with our unit protocol for early surgery comprising nerve decompression and bony stabilization within 36-hours, report excellent outcomes at medium term follow up. Conclusions We propose that nerve decompression and bony surgical stabilization should be undertaken as soon as practically possible once the diagnosis is made. This is emergent treatment to protect and preserve nerve function. In our experience, the vast majority of patients were treated within 24-hours however where a short period of observation was required excellent results were generally achieved where treatment was completed within 36-hours
Defining hierarchical protein interaction networks from spectral analysis of bacterial proteomes
Cellular behaviors emerge from layers of molecular interactions: proteins interact to form complexes, pathways, and phenotypes. We show that hierarchical networks of protein interactions can be defined from the statistical pattern of proteome variation measured across thousands of diverse bacteria and that these networks reflect the emergence of complex bacterial phenotypes. Our results are validated through gene-set enrichment analysis and comparison to existing experimentally derived databases. We demonstrate the biological utility of our approach by creating a model of motility i
The mechanical and material properties of elderly human articular cartilage subject to impact and slow loading
Copyright Ā© 2013 IPEM. Published by Elsevier Ltd. All rights reserved.Peer reviewedPostprin
Mediation of the Translocation of nNOSĪ¼ During Unloading-Induced Atrophy of Skeletal Muscle via NOX2 Inhibition
Mechanical unloading results in detachment of the mu-splice variant of neuronal nitric oxidase synthase (nNOSĪ¼) from the dystrophin-glycoprotein complex and sarcolemma and translocation to the cytosol. We recently found that reactive oxygen species (ROS) play a role in nNOSĪ¼ translocation during unloading and muscle atrophy. NOX2, an isoform of NADPH oxidase and source of ROS, may play a causal role in nNOSĪ¼ translocation. The purpose of the study was to determine the effectiveness of NOX2 peptidyl inhibition in reducing the translocation of nNOSĪ¼ from the sarcolemma and subsequently soleus CSA. Adult male Fisher 344 rats were randomly assigned to one of three groups: CON (control), HU-S (hind limb unloaded with gp91ds-tat scramble) and HU-G (hind limb unloaded with gp91ds-tat). The hind limb unloading period was 7 days. Mean body weights for CON (353.26 g Ā± 15.47), HU-S (305.14 g Ā± 18.18) and HU-G (306.34 g Ā± 16.84) at the beginning of the experiment were not significantly different. Muscle mass/body mass ratio for the gastrocnemius complex (gastrocnemius, plantaris and soleus) was significantly reduced in HU-S rats (10.08 mg/g Ā± 0.24) but was maintained in HU-G rats (10.88 mg/g Ā± 0.47). SMASH analysis revealed that average soleus CSA in HU-G rats (3293.08 Ī¼m2 Ā± 46.82) decreased significantly less than HU-S rats (2606.66 Ī¼m2 Ā± 33.46) compared with ambulatory controls (p \u3e 0.0001). Immunofluorescence and staining of nNOS activity with NADPH Diaphorase of soleus tissue showed considerable loss of sarcolemmal nNOSĪ¼ in the HU-S group while the HU-G group revealed substantial maintenance of nNOSĪ¼ at the sarcolemma. The results of this study suggest that NOX2 inhibition via gp91ds-tat is effective in reducing the translocation of nNOSĪ¼ from the sarcolemma to the cytosol and maintaining CSA of the soleus with mechanical unloading via the inhibition of NOX2
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