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Sample records for detect multiple vascular

  1. Systemic Multiple Aneurysms Caused by Vascular Ehlers-Danlos Syndrome.

    PubMed

    Gui, Xinyu; Li, Fangda; Wu, Lingeer; Zheng, Yuehong

    2016-07-01

    Systemic multiple aneurysms are rare and usually associated with collagen tissue disease, such as Ehlers-Danlos syndrome (EDS) or Marfan syndrome. In the present case, we describe a 39-year-old male patient with systemic multiple aneurysms and acute intraperitoneal hemorrhage who was clinically diagnosed with vascular EDS. Coil embolization of the distal segment of the common hepatic artery was performed, which resolved the patient's symptoms. With this case presentation, we aim to increase the awareness of vascular EDS among clinicians and emphasize the extreme fragility of the arteries in patients with vascular EDS. PMID:27206743

  2. Vascular pathology in multiple sclerosis: mind boosting or myth busting?

    PubMed Central

    2011-01-01

    The investigation of central nervous system vascular changes in the pathophysiology of multiple sclerosis (MS) is a time-honored concept. Yet, recent reports on changes in venous cerebrospinal outflow, the advent of new magnetic resonance imaging techniques and the investigation of immunomodulatory properties of several vascular mediators on the molecular level have added new excitement to hypotheses centering around vascular pathology as determining factor in the pathophysiology of MS. Here we critically review the concept of chronic cerebrospinal venous insufficiency in MS patients and describe new imaging techniques including perfusion weighted imaging, susceptibility weighted imaging and diffusion weighted imaging which reveal central nervous system hypoperfusion, perivascular iron deposition and diffuse structural changes in the MS brain. On a molecular basis, vascular mediators represent interesting targets connecting vascular pathology with immunomodulation. In summary, the relation of venous changes to the pathophysiology of MS may not be as simple as initially described and it certainly seems awkward to think of the complex disease MS solely as result of a simple venous outflow obstruction. Yet, the investigation of new vascular concepts as one variable in the pathophysiology of the autoimmune attack seems very worthwhile and may add to a better understanding of this devastating disorder. PMID:21756314

  3. Multiple vehicle detection and tracking

    NASA Astrophysics Data System (ADS)

    Betke, Margrit; Haritaoglu, Ismail; Davis, Larry S.

    1997-02-01

    A hard real time vision system has been developed that recognizes and tracks multiple cars from video sequences taken from a car driving on highways and country roads. Recognition is accomplished by combining the analysis of single image frames with the analysis of the motion information provided by multiple consecutive image frames. In single image frames, cars are recognized by matching deformable gray-scale templates, by detecting image features, such as corners, and by evaluating how these features relate to each other. Cars are also recognized by tracking motion parameters that are typical for cars. The vision system utilizes the hard real-time operating system Maruti which guarantees that the timing constraints on the various vision processes are satisfied. The dynamic creation and termination of tracking processes optimizes the amount of computational resources spent and allows fast detection and tracking of multiple cars. Experimental results demonstrate robust, real-time recognition and tracking over thousands of image frames.

  4. Infrared thermal imaging for detection of peripheral vascular disorders

    PubMed Central

    Bagavathiappan, S.; Saravanan, T.; Philip, John; Jayakumar, T.; Raj, Baldev; Karunanithi, R.; Panicker, T. M. R.; Korath, M. Paul; Jagadeesan, K.

    2009-01-01

    Body temperature is a very useful parameter for diagnosing diseases. There is a definite correlation between body temperature and diseases. We have used Infrared Thermography to study noninvasive diagnosis of peripheral vascular diseases. Temperature gradients are observed in the affected regions of patients with vascular disorders, which indicate abnormal blood flow in the affected region. Thermal imaging results are well correlated with the clinical findings. Certain areas on the affected limbs show increased temperature profiles, probably due to inflammation and underlying venous flow changes. In general the temperature contrast in the affected regions is about 0.7 to 1° C above the normal regions, due to sluggish blood circulation. The results suggest that the thermal imaging technique is an effective technique for detecting small temperature changes in the human body due to vascular disorders. PMID:20126565

  5. Vascular Multiplicity Should Not Be a Contra-Indication for Live Kidney Donation and Transplantation

    PubMed Central

    van Bruggen, Mark; Kimenai, Hendrikus J. A. N.; Tran, Thi C. K.; Terkivatan, Türkan; Betjes, Michiel G. H.; IJzermans, Jan N. M.; Dor, Frank J. M. F.

    2016-01-01

    Background Whether vascular multiplicity should be considered as contraindication and therefore ‘extended donor criterion’ is still under debate. Methods Data from all live kidney donors from 2006–2013 (n = 951) was retrospectively reviewed. Vascular anatomy as imaged by MRA, CTA or other modalities was compared with intraoperative findings. Furthermore, the influence of vascular multiplicity on outcome of donors and recipients was studied. Results In 237 out of 951 donors (25%), vascular multiplicity was present. CTA had the highest accuracy levels regarding vascular anatomy assessment. Regarding outcome of donors with vascular multiplicity, warm ischemia time (WIT) and skin-to-skin time were significantly longer if arterial multiplicity (AM) was present (5.1 vs. 4.0 mins and 202 vs. 178 mins). Skin-to-skin time was significantly longer, and complication rates were higher in donors with venous multiplicity (203 vs. 180 mins and 17.2% vs. 8.4%). Outcome of renal transplant recipients showed a significantly increased WIT (30 vs. 26.7 minutes), higher rate of DGF (13.9% vs. 6.9%) and lower rate of BPAR (6.9% vs. 13.9%) in patients receiving a kidney with AM compared to kidneys with singular anatomy. Conclusions We conclude that vascular multiplicity should not be a contra-indication, since it has little impact on clinical outcome in the donor as well as in renal transplant recipients. PMID:27077904

  6. Vascular comorbidity is associated with more rapid disability progression in multiple sclerosis

    PubMed Central

    Marrie, R.A.; Rudick, R.; Horwitz, R.; Cutter, G.; Tyry, T.; Campagnolo, D.; Vollmer, T.

    2010-01-01

    Background: Vascular comorbidity adversely influences health outcomes in several chronic conditions. Vascular comorbidities are common in multiple sclerosis (MS), but their impact on disease severity is unknown. Vascular comorbidities may contribute to the poorly understood heterogeneity in MS disease severity. Treatment of vascular comorbidities may represent an avenue for treating MS. Methods: A total of 8,983 patients with MS enrolled in the North American Research Committee on Multiple Sclerosis Registry participated in this cohort study. Time from symptom onset or diagnosis until ambulatory disability was compared for patients with or without vascular comorbidities to determine their impact on MS severity. Multivariable proportional hazards models were adjusted for sex, race, age at symptom onset, year of symptom onset, socioeconomic status, and region of residence. Results: Participants reporting one or more vascular comorbidities at diagnosis had an increased risk of ambulatory disability, and risk increased with the number of vascular conditions reported (hazard ratio [HR]/condition for early gait disability 1.51; 95% confidence interval [CI] 1.41–1.61). Vascular comorbidity at any time during the disease course also increased the risk of ambulatory disability (adjusted HR for unilateral walking assistance 1.54; 95% CI 1.44–1.65). The median time between diagnosis and need for ambulatory assistance was 18.8 years in patients without and 12.8 years in patients with vascular comorbidities. Conclusions: Vascular comorbidity, whether present at symptom onset, diagnosis, or later in the disease course, is associated with a substantially increased risk of disability progression in multiple sclerosis. The impact of treating vascular comorbidities on disease progression deserves investigation. GLOSSARY EDSS = Expanded Disability Status Scale; HR = hazard ratio; MS = multiple sclerosis; NARCOMS = North American Research Committee on Multiple Sclerosis; PDDS

  7. Multi-lane detection based on multiple vanishing points detection

    NASA Astrophysics Data System (ADS)

    Li, Chuanxiang; Nie, Yiming; Dai, Bin; Wu, Tao

    2015-03-01

    Lane detection plays a significant role in Advanced Driver Assistance Systems (ADAS) for intelligent vehicles. In this paper we present a multi-lane detection method based on multiple vanishing points detection. A new multi-lane model assumes that a single lane, which has two approximately parallel boundaries, may not parallel to others on road plane. Non-parallel lanes associate with different vanishing points. A biological plausibility model is used to detect multiple vanishing points and fit lane model. Experimental results show that the proposed method can detect both parallel lanes and non-parallel lanes.

  8. Fast automatic algorithm for bifurcation detection in vascular CTA scans

    NASA Astrophysics Data System (ADS)

    Brozio, Matthias; Gorbunova, Vladlena; Godenschwager, Christian; Beck, Thomas; Bernhardt, Dominik

    2012-02-01

    Endovascular imaging aims at identifying vessels and their branches. Automatic vessel segmentation and bifurcation detection eases both clinical research and routine work. In this article a state of the art bifurcation detection algorithm is developed and applied on vascular computed tomography angiography (CTA) scans to mark the common iliac artery and its branches, the internal and external iliacs. In contrast to other methods our algorithm does not rely on a complete segmentation of a vessel in the 3D volume, but evaluates the cross-sections of the vessel slice by slice. Candidates for vessels are obtained by thresholding, following by 2D connected component labeling and prefiltering by size and position. The remaining candidates are connected in a squared distanced weighted graph. With Dijkstra algorithm the graph is traversed to get candidates for the arteries. We use another set of features considering length and shape of the paths to determine the best candidate and detect the bifurcation. The method was tested on 119 datasets acquired with different CT scanners and varying protocols. Both easy to evaluate datasets with high resolution and no apparent clinical diseases and difficult ones with low resolution, major calcifications, stents or poor contrast between the vessel and surrounding tissue were included. The presented results are promising, in 75.7% of the cases the bifurcation was labeled correctly, and in 82.7% the common artery and one of its branches were assigned correctly. The computation time was on average 0.49 s +/- 0.28 s, close to human interaction time, which makes the algorithm applicable for time-critical applications.

  9. Interger multiplication with overflow detection or saturation

    SciTech Connect

    Schulte, M.J.; Balzola, P.I.; Akkas, A.; Brocato, R.W.

    2000-01-11

    High-speed multiplication is frequently used in general-purpose and application-specific computer systems. These systems often support integer multiplication, where two n-bit integers are multiplied to produce a 2n-bit product. To prevent growth in word length, processors typically return the n least significant bits of the product and a flag that indicates whether or not overflow has occurred. Alternatively, some processors saturate results that overflow to the most positive or most negative representable number. This paper presents efficient methods for performing unsigned or two's complement integer multiplication with overflow detection or saturation. These methods have significantly less area and delay than conventional methods for integer multiplication with overflow detection and saturation.

  10. Choosing Small Weights For Multiple Error Detection

    NASA Astrophysics Data System (ADS)

    Brent, Richard P.; Luk, Franklin T.; Anfinson, Cynthia J.

    1989-05-01

    The weighted checksum technique has been demonstrated to be effective in multiple error detection. It has been shown that, in order to guarantee error detection, the chosen weight vectors must satisfy some very specific properties about linear independence. Previous weight generating methods that fulfill the independence criteria have problems with numerical overflow. We present a new scheme that generates weight vectors to meet the requirements about independence and to avoid the difficulties with overflow.

  11. Detection algorithm for multiple rice seeds images

    NASA Astrophysics Data System (ADS)

    Cheng, F.; Ying, Y. B.

    2006-10-01

    The objective of this research is to develop a digital image analysis algorithm for detection of multiple rice seeds images. The rice seeds used for this study involved a hybrid rice seed variety. Images of multiple rice seeds were acquired with a machine vision system for quality inspection of bulk rice seeds, which is designed to inspect rice seeds on a rotating disk with a CCD camera. Combining morphological operations and parallel processing gave improvements in accuracy, and a reduction in computation time. Using image features selected based on classification ability; a highly acceptable defects classification was achieved when the algorithm was implemented for all the samples to test the adaptability.

  12. Decreased Endothelin-1 Plasma Levels in Multiple Sclerosis Patients: A Possible Factor of Vascular Dysregulation?

    PubMed Central

    Jankowska-Lech, Irmina; Terelak-Borys, Barbara; Grabska-Liberek, Iwona; Palasik, Witold; Bik, Wojciech; Wolińska-Witort, Ewa

    2015-01-01

    Background Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system with possible involvement of vascular dysregulation secondary to endothelial dysfunction caused by destruction of the vessel wall. Vascular dysregulation leads to excessive vasoconstriction or insufficient vasodilatation, resulting in vasospasm mediated by endothelin-1 (ET-1), the most potent and long-lasting mediator. Vascular dysregulation can play an important role in the pathogenesis of some eye disorders and it has been hypothesized that it is a vascular risk factor for glaucomatous optic neuropathy. The aim of this study was to estimate endothelin-1 (ET-1) plasma levels in patients with MS. Material/Methods The MS group consisted of 39 patients (9 males, 30 females), mean age: 38.8±10.02 years, range: 22–62. The control group consisted of 27 healthy volunteers (3 males and 24 females), mean age: 37.4±10.88 years, range: 20–62; clinically, in a non-active stage of the disease. ET-1 plasma levels were measured using the Endothelin-1 ELISA Kit (Immuno-Biological Laboratories Co., Japan). Statistical analysis was performed with the nonparametric Mann-Whitney U test for independent groups. Results Endothelin-1 (ET-1) plasma levels were significantly lower in MS patients compared to healthy controls: mean value 0.55±0.44 pg/ml (146.05±118.27 fmol/ml) vs. 0.95±0.48 pg/ml (252.83±127.16 fmol/ml); P=0.012. Conclusions Significantly decreased ET-1 plasma levels in the MS patients could reflect the non-active disease at the time of ET-1 measurements or the effects of immunomodulatory treatment, but it cannot be excluded that decreased ET-1 plasma levels in these patients might result from vascular dysregulation. PMID:25864450

  13. Permeation absorption sampler with multiple detection

    DOEpatents

    Zaromb, Solomon

    1990-01-01

    A system for detecting analytes in air or aqueous systems includes a permeation absorption preconcentrator sampler for the analytes and analyte detectors. The preconcentrator has an inner fluid-permeable container into which a charge of analyte-sorbing liquid is intermittently injected, and a fluid-impermeable outer container. The sample is passed through the outer container and around the inner container for trapping and preconcentrating the analyte in the sorbing liquid. The analyte can be detected photometrically by injecting with the sorbing material a reagent which reacts with the analyte to produce a characteristic color or fluorescence which is detected by illuminating the contents of the inner container with a light source and measuring the absorbed or emitted light, or by producing a characteristic chemiluminescence which can be detected by a suitable light sensor. The analyte can also be detected amperometrically. Multiple inner containers may be provided into which a plurality of sorbing liquids are respectively introduced for simultaneously detecting different analytes. Baffles may be provided in the outer container. A calibration technique is disclosed.

  14. Detection of intrusion across multiple sensors

    NASA Astrophysics Data System (ADS)

    Long, William J.; Doyle, Jon; Burke, Glenn; Szolovits, Peter

    2003-08-01

    We have been developing an architecture for reasoning with multiple sensors distributed on a computer network, linking them with analysis modules and reasoning with the results to combine evidence of possible intrusion for display to the user. The architecture, called MAITA, consists of monitors distributed across machines and linked together under control of the user and supported by a monitor of monitors that manages the interaction among the monitors. This architecture enables the system to reason about evidence from multiple sensors. For example, a monitor can track FTP logs to detect password scans followed by successful uploads of data from foreign sites. At the same time it can monitor disk use and detect significant trends. Monitors can then combine the evidence in the sequence in which they occur and present evidence to the user that someone has successfully gained write access to the FTP site and is occupying significant disk space. This paper discusses the architecture enabling the creation, linking, and support of the monitors. The monitors may be running on the same or different machines and so appropriate communication links must be supported as well as regular status checks to ensure that monitors are still running. We will also discuss the construction of monitors for sensing the data, abstracting and characterizing data, synchronizing data from different sources, detecting patterns, and displaying the results.

  15. Effects of the detection efficiency on multiplicity distributions

    NASA Astrophysics Data System (ADS)

    Tang, A. H.; Wang, G.

    2013-08-01

    In this paper we investigate how a finite detection efficiency affects three popular multiplicity distributions, namely, the Poisson, the binomial, and the negative binomial distributions. We found that a multiplicity-independent detection efficiency does not change the characteristic of a distribution, while a multiplicity-dependent detection efficiency does. We layout a procedure to study the deviation of moments and their derivative quantities from the baseline distribution due to a multiplicity-dependent detection efficiency.

  16. Self-contained diffuse optical imaging system for real-time detection and localization of vascular occlusions.

    PubMed

    Pollonini, Luca; Forseth, Kiefer J; Dacso, Clifford C; Parazynski, Scott E; Friedman, Jeffrey D

    2015-08-01

    Free flap surgery is a procedure where healthy tissue is transferred from a donor site to a recipient site of the body to fill a defect without maintaining the original blood supply to the flap. The anastomosis of the vascular network of the flap to the blood vessels adjacent to the recipient site has associated risks of arterial and/or venous occlusions that must be promptly detected to avoid temporary or permanent tissue damage. In this work, we present a skin-contact diffusion optical imaging (DOI) system able to continuously provide a three-dimensional representation of the flap oxygenation to promptly detect vascular occlusions potentially occurring in the flap. Multiple near-infrared LEDs and photodetectors were embedded into a self-contained optical sensor for prolonged monitoring of concentration changes of oxygenated (HbO) and deoxygenated hemoglobin (HbR) at multiple locations and depths. A time-efficient algorithm mapped measured oxygenation changes in a three-dimensional volume to allow surgeons and clinical personnel to detect and localize abnormal blood perfusion changes during or after surgery, in time for corrective intervention. The image reconstruction algorithm was validated using computerized flap models in which oxygenation was synthetically altered, whereas the optical system was preliminarily tested on a healthy forearm simulating a flap undergoing arterial and venous occlusions, proving the feasibility of implementing DOI in the form of a wearable patch for prolonged perfusion monitoring. PMID:26737630

  17. Simulated unobtrusive falls detection with multiple persons.

    PubMed

    Ariani, Arni; Redmond, Stephen J; Chang, David; Lovell, Nigel H

    2012-11-01

    One serious issue related to falls among the elderly living at home or in a residential care facility is the "long lie" scenario, which involves being unable to get up from the floor after a fall for 60 min or more. This research uses a simulated environment to investigate the potential effectiveness of using wireless ambient sensors (dual-technology (microwave/infrared) motion detectors and pressure mats) to track the movement of multiple persons and to unobtrusively detect falls when they occur, therefore reducing the rate of occurrence of "long lie" scenarios. A path-finding algorithm (A*) is used to simulate the movement of one or more persons through the residential area. For analysis, the sensor network is represented as an undirected graph, where nodes in the graph represent sensors, and edges between nodes in the graph imply that these sensors share an overlapping physical region in their area of sensitivity. A second undirected graph is used to represent the physical adjacency of the sensors (even where they do not overlap in their monitored regions). These graphical representations enable the tracking of multiple subjects/groups within the environment, by analyzing the sensor activation and adjacency profiles, hence allowing individuals/groups to be isolated when multiple persons are present, and subsequently monitoring falls events. A falls algorithm, based on a heuristic decision tree classifier model, was tested on 15 scenarios, each including one or more persons; three scenarios of activity of daily living, and 12 different types of falls (four types of fall, each with three postfall scenarios). The sensitivity, specificity, and accuracy of the falls algorithm are 100.00%, 77.14%, and 89.33%, respectively. PMID:22835529

  18. A Non-Parametric Vessel Detection Method for Complex Vascular Structures

    PubMed Central

    Qian, Xiaoning; Brennan, Matthew P.; Dione, Donald P.; Dobrucki, Wawrzyniec L.; Jackowski, Marcel P.; Breuer, Christopher K.; Sinusas, Albert J.; Papademetris, Xenophon

    2008-01-01

    Modern medical imaging techniques enable the acquisition of in-vivo high resolution images of the vascular system. Most common methods for the detection of vessels in these images, such as multiscale Hessian-based operators and matched filters, rely on the assumption that at each voxel there is a single cylinder. Such an assumption is clearly violated at the multitude of branching points that are easily observed in all but the most focused vascular image studies. In this paper, we propose a novel method for detecting vessels in medical images that relaxes this single cylinder assumption. We directly exploit local neighborhood intensities and extract characteristics of the local intensity profile (in a spherical polar coordinate system) which we term as the polar neighborhood intensity profile. We present a new method to capture the common properties shared by polar neighborhood intensity profiles for all the types of vascular points belonging to the vascular system. The new method enables us to detect vessels even near complex extreme points, including branching points. Our method demonstrates improved performance over standard methods on both 2D synthetic images and 3D animal and clinical vascular images, particularly close to vessel branching regions. PMID:18678521

  19. Non-expanded adipose stromal vascular fraction cell therapy for multiple sclerosis

    PubMed Central

    Riordan, Neil H; Ichim, Thomas E; Min, Wei-Ping; Wang, Hao; Solano, Fabio; Lara, Fabian; Alfaro, Miguel; Rodriguez, Jorge Paz; Harman, Robert J; Patel, Amit N; Murphy, Michael P; Lee, Roland R; Minev, Boris

    2009-01-01

    The stromal vascular fraction (SVF) of adipose tissue is known to contain mesenchymal stem cells (MSC), T regulatory cells, endothelial precursor cells, preadipocytes, as well as anti-inflammatory M2 macrophages. Safety of autologous adipose tissue implantation is supported by extensive use of this procedure in cosmetic surgery, as well as by ongoing studies using in vitro expanded adipose derived MSC. Equine and canine studies demonstrating anti-inflammatory and regenerative effects of non-expanded SVF cells have yielded promising results. Although non-expanded SVF cells have been used successfully in accelerating healing of Crohn's fistulas, to our knowledge clinical use of these cells for systemic immune modulation has not been reported. In this communication we discuss the rationale for use of autologous SVF in treatment of multiple sclerosis and describe our experiences with three patients. Based on this rationale and initial experiences, we propose controlled trials of autologous SVF in various inflammatory conditions. PMID:19393041

  20. Lymphatics in Neurological Disorders: A Neuro-Lympho-Vascular Component of Multiple Sclerosis and Alzheimer's Disease?

    PubMed

    Louveau, Antoine; Da Mesquita, Sandro; Kipnis, Jonathan

    2016-09-01

    Lymphatic vasculature drains interstitial fluids, which contain the tissue's waste products, and ensures immune surveillance of the tissues, allowing immune cell recirculation. Until recently, the CNS was considered to be devoid of a conventional lymphatic vasculature. The recent discovery in the meninges of a lymphatic network that drains the CNS calls into question classic models for the drainage of macromolecules and immune cells from the CNS. In the context of neurological disorders, the presence of a lymphatic system draining the CNS potentially offers a new player and a new avenue for therapy. In this review, we will attempt to integrate the known primary functions of the tissue lymphatic vasculature that exists in peripheral organs with the proposed function of meningeal lymphatic vessels in neurological disorders, specifically multiple sclerosis and Alzheimer's disease. We propose that these (and potentially other) neurological afflictions can be viewed as diseases with a neuro-lympho-vascular component and should be therapeutically targeted as such. PMID:27608759

  1. Electrochemical Detection of Multiple Bioprocess Analytes

    NASA Technical Reports Server (NTRS)

    Rauh, R. David

    2010-01-01

    An apparatus that includes highly miniaturized thin-film electrochemical sensor array has been demonstrated as a prototype of instruments for simultaneous detection of multiple substances of interest (analytes) and measurement of acidity or alkalinity in bioprocess streams. Measurements of pH and of concentrations of nutrients and wastes in cell-culture media, made by use of these instruments, are to be used as feedback for optimizing the growth of cells or the production of desired substances by the cultured cells. The apparatus is designed to utilize samples of minimal volume so as to minimize any perturbation of monitored processes. The apparatus can function in a potentiometric mode (for measuring pH), an amperometric mode (detecting analytes via oxidation/reduction reactions), or both. The sensor array is planar and includes multiple thin-film microelectrodes covered with hydrous iridium oxide. The oxide layer on each electrode serves as both a protective and electrochemical transducing layer. In its transducing role, the oxide provides electrical conductivity for amperometric measurement or pH response for potentiometric measurement. The oxide on an electrode can also serve as a matrix for one or more enzymes that render the electrode sensitive to a specific analyte. In addition to transducing electrodes, the array includes electrodes for potential control. The array can be fabricated by techniques familiar to the microelectronics industry. The sensor array is housed in a thin-film liquid-flow cell that has a total volume of about 100 mL. The flow cell is connected to a computer-controlled subsystem that periodically draws samples from the bioprocess stream to be monitored. Before entering the cell, each 100-mL sample is subjected to tangential-flow filtration to remove particles. In the present version of the apparatus, the electrodes are operated under control by a potentiostat and are used to simultaneously measure the pH and the concentration of glucose

  2. Multiple symbol partially coherent detection of MPSK

    NASA Technical Reports Server (NTRS)

    Simon, M. K.; Divsalar, D.

    1992-01-01

    It is shown that by using the known (or estimated) value of carrier tracking loop signal to noise ratio (SNR) in the decision metric, it is possible to improve the error probability performance of a partially coherent multiple phase-shift-keying (MPSK) system relative to that corresponding to the commonly used ideal coherent decision rule. Using a maximum-likeihood approach, an optimum decision metric is derived and shown to take the form of a weighted sum of the ideal coherent decision metric (i.e., correlation) and the noncoherent decision metric which is optimum for differential detection of MPSK. The performance of a receiver based on this optimum decision rule is derived and shown to provide continued improvement with increasing length of observation interval (data symbol sequence length). Unfortunately, increasing the observation length does not eliminate the error floor associated with the finite loop SNR. Nevertheless, in the limit of infinite observation length, the average error probability performance approaches the algebraic sum of the error floor and the performance of ideal coherent detection, i.e., at any error probability above the error floor, there is no degradation due to the partial coherence. It is shown that this limiting behavior is virtually achievable with practical size observation lengths. Furthermore, the performance is quite insensitive to mismatch between the estimate of loop SNR (e.g., obtained from measurement) fed to the decision metric and its true value. These results may be of use in low-cost Earth-orbiting or deep-space missions employing coded modulations.

  3. Detection of atherosclerotic vascular tissue from optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Prakash, Ammu; Hewko, Mark; Sowa, Mike; Sherif, Sherif

    2012-10-01

    Atherosclerotic coronary artery disease continues to be one of the major causes of mortality. Prevention, diagnosis and treatment of atherosclerotic coronary artery disease are dependent on the detection of high risk atherosclerotic plaque. As age is one of the most important risk factors, atherosclerosis worsens steadily with increasing age. Automatic characterization of atherosclerotic plaque using the optical coherence tomography (OCT) images provides a powerful tool to classify patients with high risk plaque. In this study we develop an automatic classifier to detect atherosclerotic plaque in young and old Watanabe heritable hyperlipidemic (WHHL) rabbits, using OCT images without reliance on visual inspection. Our classifier based on texture analysis technique may provide an efficient tool for detecting invisible changes in tissue structure. We extracted a set of 22 statistical textural features for each image using the spatial gray level dependence matrix (SGLDM) method. An optimal scalar feature selection process was carried to select the best discriminating features that employ the Fisher discriminant ratio (FDR) criterion, and cross correlation measure between the pairs of features. Using these optimal features, we formed a combination of 5 best classification features using an exhaustive search method. A combined feature set was finally employed for the classification of plaque. We obtained correct classification rate and validation of 76.67% and 75% respectively.

  4. Detecting abandoned objects using interacting multiple models

    NASA Astrophysics Data System (ADS)

    Becker, Stefan; Münch, David; Kieritz, Hilke; Hübner, Wolfgang; Arens, Michael

    2015-10-01

    In recent years, the wide use of video surveillance systems has caused an enormous increase in the amount of data that has to be stored, monitored, and processed. As a consequence, it is crucial to support human operators with automated surveillance applications. Towards this end an intelligent video analysis module for real-time alerting in case of abandoned objects in public spaces is proposed. The overall processing pipeline consists of two major parts. First, person motion is modeled using an Interacting Multiple Model (IMM) filter. The IMM filter estimates the state of a person according to a finite-state, discrete-time Markov chain. Second, the location of persons that stay at a fixed position defines a region of interest, in which a nonparametric background model with dynamic per-pixel state variables identifies abandoned objects. In case of a detected abandoned object, an alarm event is triggered. The effectiveness of the proposed system is evaluated on the PETS 2006 dataset and the i-Lids dataset, both reflecting prototypical surveillance scenarios.

  5. Application of vascular bundle displacement in the optic disc for glaucoma detection using fundus images.

    PubMed

    Fuente-Arriaga, José Abel de la; Felipe-Riverón, Edgardo M; Garduño-Calderón, Eduardo

    2014-04-01

    This paper presents a methodology for glaucoma detection based on measuring displacements of blood vessels within the optic disc (vascular bundle) in human retinal images. The method consists of segmenting the region of the vascular bundle in an optic disc to set a reference point in the temporal side of the cup, determining the position of the centroids of the superior, inferior, and nasal vascular bundle segmented zones located within the segmented region, and calculating the displacement from normal position using the chessboard distance metric. The method was successful in 62 images out of 67, achieving 93.02% sensitivity, 91.66% specificity, and 91.34% global accuracy in pre-diagnosis. PMID:24530536

  6. [Primary Study on Noninvasive Detection of Vascular Function Based on Finger Temperature Change].

    PubMed

    Dong, Qing; Li, Xia; Wan, Yungao; Lu, Gaoquan; Wang, Xinxin; Zhang, Kuan

    2016-02-01

    By studying the relationship between fingertip temperature changes and arterial function during vascular reactivity test, we established a new non-invasive method for detecting vascular function, in order to provide an assistance for early diagnosis and prevention of cardiovascular diseases. We customized three modules respectively for blood occlusion, measurement of finger temperature and blood oxygen acquisition, and then we established the hardware of data acquisition system. And the software was programmed with Labview. Healthy subjects [group A, n = 24, (44.6 ± 9.0) years] and subjects with cardiovascular diseases [group B, n = 33, (57.2 ± 9.9) years)] were chosen for the study. Subject's finger temperature, blood oxygen and occlusion pressure of block side during and after unilateral arm brachial artery occlusion were recorded, as well as some other regular physiological indexes. By time-domain analysis, we extracted 12 parameters from fingertip temperature signal, including the initial temperature (Ti), temperature rebound (TR), the time of the temperature recovering to initial status (RIt) and other parameters from the finger temperature signal. We in the experiment also measured other regular physiological body mass index (BMI), systolic blood pressure (SBP), diastiolic blood pressure (DBP) and so on. Results showed that 8 parameters difference between the two group of data were significant. based on the statistical results. A discriminant function of vascular function status was established afterwards. We found in the study that the changes of finger temperature during unilateral arms brachial artery occlusion and open were closely related to vascular function. We hope that the method presented in this article could lay a foundation of early detection of vascular function. PMID:27382755

  7. Multiple Signaling Pathways Contribute to the Thrombin-induced Secretory Phenotype in Vascular Smooth Muscle Cells

    PubMed Central

    Jeong, Ji Young; Son, Younghae; Kim, Bo-Young; Eo, Seong-Kug; Rhim, Byung-Yong

    2015-01-01

    We attempted to investigate molecular mechanisms underlying phenotypic change of vascular smooth muscle cells (VSMCs) by determining signaling molecules involved in chemokine production. Treatment of human aortic smooth muscle cells (HAoSMCs) with thrombin resulted not only in elevated transcription of the (C-C motif) ligand 11 (CCL11) gene but also in enhanced secretion of CCL11 protein. Co-treatment of HAoSMCs with GF109230X, an inhibitor of protein kinase C, or GW5074, an inhibitor of Raf-1 kinase, caused inhibition of ERK1/2 phosphorylation and significantly attenuated expression of CCL11 at transcriptional and protein levels induced by thrombin. Both Akt phosphorylation and CCL11 expression induced by thrombin were attenuated in the presence of pertussis toxin (PTX), an inhibitor of Gi protein-coupled receptor, or LY294002, a PI3K inhibitor. In addition, thrombin-induced production of CCL11 was significantly attenuated by pharmacological inhibition of Akt or MEK which phosphorylates ERK1/2. These results indicate that thrombin is likely to promote expression of CCL11 via PKC/Raf-1/ERK1/2 and PTX-sensitive protease-activated receptors/PI3K/Akt pathways in HAoSMCs. We propose that multiple signaling pathways are involved in change of VSMCs to a secretory phenotype. PMID:26557022

  8. Multiple Signaling Pathways Contribute to the Thrombin-induced Secretory Phenotype in Vascular Smooth Muscle Cells.

    PubMed

    Jeong, Ji Young; Son, Younghae; Kim, Bo-Young; Eo, Seong-Kug; Rhim, Byung-Yong; Kim, Koanhoi

    2015-11-01

    We attempted to investigate molecular mechanisms underlying phenotypic change of vascular smooth muscle cells (VSMCs) by determining signaling molecules involved in chemokine production. Treatment of human aortic smooth muscle cells (HAoSMCs) with thrombin resulted not only in elevated transcription of the (C-C motif) ligand 11 (CCL11) gene but also in enhanced secretion of CCL11 protein. Co-treatment of HAoSMCs with GF109230X, an inhibitor of protein kinase C, or GW5074, an inhibitor of Raf-1 kinase, caused inhibition of ERK1/2 phosphorylation and significantly attenuated expression of CCL11 at transcriptional and protein levels induced by thrombin. Both Akt phosphorylation and CCL11 expression induced by thrombin were attenuated in the presence of pertussis toxin (PTX), an inhibitor of Gi protein-coupled receptor, or LY294002, a PI3K inhibitor. In addition, thrombin-induced production of CCL11 was significantly attenuated by pharmacological inhibition of Akt or MEK which phosphorylates ERK1/2. These results indicate that thrombin is likely to promote expression of CCL11 via PKC/Raf-1/ERK1/2 and PTX-sensitive protease-activated receptors/PI3K/Akt pathways in HAoSMCs. We propose that multiple signaling pathways are involved in change of VSMCs to a secretory phenotype. PMID:26557022

  9. Incidentally Detected Mediastinal Vascular Anatomical Variants on PET-CT: A Pictorial Essay

    PubMed Central

    Paidipati, Kathyayini Gopalkrishna Murthy; Kashyap, Raghava; Tadimeti, Hima; Peyyeti, Mahidhar

    2015-01-01

    Positron emission tomography with computed tomography (PET–CT) is an integral part of oncology practice in the current-day scenario. The hybrid anatomical and metabolic imaging information in this imaging modality provides access to a wealth of incidental findings which can have implications in the management of the patient, especially when surgical options are being considered. In this pictorial essay, we present incidentally detected mediastinal vascular anomalies on PET–CT, along with a review of associated literature. PMID:25883859

  10. Detecting the Multiple Facets of Biodiversity.

    PubMed

    Jarzyna, Marta A; Jetz, Walter

    2016-07-01

    Interest in, and opportunities to include functional and phylogenetic attributes of species in community ecology and biogeography are rapidly growing and seen as vital for the assessment of status and trends in biodiversity. However, the fundamental underlying evidence remains the (co-)occurrence of the biological units, such as species, in time and space and our ability to appropriately detect and quantify them. Here, we examine the implications of imperfect detection of species for functional and phylogenetic diversity (FD and PD) estimates. We explore how FD and PD might have different detectabilities than taxonomic diversity (TD) and how all three might vary differently along spatial and environmental gradients. We also extend occupancy modeling and dendrogram-based methods to address the imperfect detection of different biodiversity facets. PMID:27168115

  11. Detection of dim targets in multiple environments

    NASA Astrophysics Data System (ADS)

    Mirsky, Grace M.; Woods, Matthew; Grasso, Robert J.

    2013-10-01

    The proliferation of a wide variety of weapons including Anti-Aircraft Artillery (AAA), rockets, and small arms presents a substantial threat to both military and civilian aircraft. To address this ever-present threat, Northrop Grumman has assessed unguided threat phenomenology to understand the underlying physical principles for detection. These principles, based upon threat transit through the atmosphere, exploit a simple phenomenon universal to all objects moving through an atmosphere comprised of gaseous media to detect and track the threat in the presence of background and clutter. Threat detection has rapidly become a crucial component of aircraft survivability systems that provide situational awareness to the crew. It is particularly important to platforms which may spend a majority of their time at low altitudes and within the effective range of a large variety of weapons. Detection of these threats presents a unique challenge as this class of threat typically has a dim signature coupled with a short duration. Correct identification of each of the threat components (muzzle flash and projectile) is important to determine trajectory and intent while minimizing false alarms and maintaining a high detection probability in all environments.

  12. Multiple instance learning for buried hazard detection

    NASA Astrophysics Data System (ADS)

    Rice, Joseph; Pinar, Anthony; Havens, Timothy C.; Webb, Adam; Schulz, Timothy J.

    2016-05-01

    Buried explosives hazards are one of the many deadly threats facing our Soldiers, thus the U.S. Army is interested in the detection and neutralization of these hazards. One method of buried target detection uses forward-looking ground-penetrating radar (FLGPR), and it has grown in popularity due to its ability to detect buried targets at a standoff distance. FLGPR approaches often use machine learning techniques to improve the accuracy of detection. We investigate an approach to explosive hazard detection that exploits multi-instance features to discriminate between hazardous and non-hazardous returns in FLGPR data. One challenge this problem presents is a high number of clutter and non-target objects relative to the number of targets present. Our approach learns a bag of words model of the multi-instance signatures of potential targets and confuser objects in order to classify alarms as either targets or false alarms. We demonstrate our method on test data collected at a U.S. Army test site.

  13. Vascular Ehlers-Danlos syndrome presenting as rapidly progressive multiple arterial aneurysms and dissections.

    PubMed

    Mortani Barbosa, Eduardo J; Pyeritz, Reed E; Litt, Harold; Desjardins, Benoit

    2011-12-01

    Life expectancy in vascular Ehlers-Danlos syndrome (EDS) is shortened due to spontaneous rupture of arteries, the colon and the gravid uterus. Two adolescent males with vascular EDS illustrate rapid progression of arterial aneurysms, dissections, and rupture. Radiologic imaging played an important role in initially diagnosing and monitoring the evolution of arterial involvement. Both prophylactic and emergency management remain largely ineffective in this connective tissue disorder; however, noninvasive imaging may provide important prognostic information. PMID:22065459

  14. Phylogenetic analysis and positive-selection site detecting of vascular endothelial growth factor family in vertebrates.

    PubMed

    He, Wenwu; Tang, Yanyan; Qi, Bin; Lu, Chuansen; Qin, Chao; Wei, Yunfei; Yi, Jiachao; Chen, Mingwu

    2014-02-10

    Vascular endothelial growth factor (VEGF), known to play an important role in vascular homeostasis, vascular integrity and angiogenesis, is little known about the evolutionary relationship of its five members especially the role of gene duplication and natural selection in the evolution of the VEGF family. In this study, seventy-five full-length cDNA sequences from 33 vertebrate species were extracted from the NCBI's GenBank, UniProt protein database and the Ensembl database. By phylogenetic analyses, we investigated the origin, conservation, and evolution of the VEGFs. Five VEGF family members in vertebrates might be formed by gene duplication. The inferred evolutionary transitions that separate members which belong to different gene clusters correlated with changes in functional properties. Selection analysis and protein structure analysis were combined to explain the relationship of the site-specific evolution in the vertebrate VEGF family. Eleven positive selection sites, one transmembrane region and the active sites were detected in this process. PMID:24200960

  15. A novel vascular disrupting agent plinabulin triggers JNK-mediated apoptosis and inhibits angiogenesis in multiple myeloma cells.

    PubMed

    Singh, Ajita V; Bandi, Madhavi; Raje, Noopur; Richardson, Paul; Palladino, Michael A; Chauhan, Dharminder; Anderson, Kenneth C

    2011-05-26

    Previous studies have established a role of vascular-disrupting agents as anti- cancer agents. Plinabulin is a novel vascular-disrupting agent that exhibits potent interruption of tumor blood flow because of the disruption of tumor vascular endothelial cells, resulting in tumor necrosis. In addition, plinabulin exerts a direct action on tumor cells, resulting in apoptosis. In the present study, we examined the anti-multiple myeloma (MM) activity of plinabulin. We show that low concentrations of plinabulin exhibit a potent antiangiogenic action on vascular endothelial cells. Importantly, plinabulin also induces apoptotic cell death in MM cell lines and tumor cells from patients with MM, associated with mitotic growth arrest. Plinabulin-induced apoptosis is mediated through activation of caspase-3, caspase-8, caspase-9, and poly(ADP-ribose) polymerase cleavage. Moreover, plinabulin triggered phosphorylation of stress response protein JNK, as a primary target, whereas blockade of JNK with a biochemical inhibitor or small interfering RNA strategy abrogated plinabulin-induced mitotic block or MM cell death. Finally, in vivo studies show that plinabulin was well tolerated and significantly inhibited tumor growth and prolonged survival in a human MM.1S plasmacytoma murine xenograft model. Our study therefore provides the rationale for clinical evaluation of plinabulin to improve patient outcome in MM. PMID:21454451

  16. Detection of Differential Item Functioning in Multiple Groups.

    ERIC Educational Resources Information Center

    Kim, Seock-Ho; And Others

    Detection of differential item functioning (DIF) is most often done between two groups of examinees under item response theory. It is sometimes important, however, to determine whether DIF is present in more than two groups. A method is presented for the detection of DIF in multiple groups. The method, the Q(sub j) statistic, is closely related to…

  17. Resonant tunneling diode with a multiplication region for light detection

    NASA Astrophysics Data System (ADS)

    Dong, Yu; Wang, Guanglong; Ni, Haiqiao; Chen, Jianhui; Gao, Fengqi; Qiao, Zhongtao; Niu, Zhichuan

    2014-11-01

    A resonant tunneling diode (RTD) with a multiplication region is designed for light detection in this paper. Via adding a n+-i-p+ multiplication region, we focus on promoting the photocurrent and light sensitivity of the detector. Through the calculation of the multiplication factor, the thickness of the multiplication region is determined. The influence factors of the electric field and potential distribution of the detector are investigated, thereby the thickness and doping concentration of the doped layers besides the double-barrier structure (DBS) are decided. Detectors with and without a multiplication region are fabricated from semiconductor heterostructures grown by molecular beam epitaxy. The current-voltage (I-V) and light sensitivity tests show that the detector with a multiplication region has better performance in peak photocurrent and light sensitivity.

  18. Multiple biomarkers and risk of clinical and subclinical vascular brain injury: the framingham offspring study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several biomarkers have been individually associated with vascular brain injury, but no prior study has explored the simultaneous association of a biologically plausible panel of biomarkers with the incidence of stroke/transient ischemic attack and the prevalence of subclinical brain injury. In 3127...

  19. Automatic detection of bioresorbable vascular scaffold struts in intravascular optical coherence tomography pullback runs

    PubMed Central

    Wang, Ancong; Nakatani, Shimpei; Eggermont, Jeroen; Onuma, Yoshi; Garcia-Garcia, Hector M.; Serruys, Patrick W.; Reiber, Johan H.C.; Dijkstra, Jouke

    2014-01-01

    Bioresorbable vascular scaffolds (BVS) have gained significant interest in both the technical and clinical communities as a possible alternative to metallic stents. For accurate BVS analysis, intravascular optical coherence tomography (IVOCT) is currently the most suitable imaging technique due to its high resolution and the translucency of polymeric BVS struts for near infrared light. However, given the large number of struts in an IVOCT pullback run, quantitative analysis is only feasible when struts are detected automatically. In this paper, we present an automated method to detect and measure BVS struts based on their black cores in IVOCT images. Validated using 3 baseline and 3 follow-up data sets, the method detected 93.7% of 4691 BVS struts correctly with 1.8% false positives. In total, the Dice’s coefficient for BVS strut areas was 0.84. It concludes that this method can detect BVS struts accurately and robustly for tissue coverage measurement, malapposition detection, strut distribution analysis or 3D scaffold reconstruction. PMID:25360375

  20. Retinal vascular biomarkers for early detection and monitoring of Alzheimer's disease

    PubMed Central

    Frost, S; Kanagasingam, Y; Sohrabi, H; Vignarajan, J; Bourgeat, P; Salvado, O; Villemagne, V; Rowe, C C; Lance Macaulay, S; Szoeke, C; Ellis, K A; Ames, D; Masters, C L; Rainey-Smith, S; Martins, R N

    2013-01-01

    The earliest detectable change in Alzheimer's disease (AD) is the buildup of amyloid plaque in the brain. Early detection of AD, prior to irreversible neurological damage, is important for the efficacy of current interventions as well as for the development of new treatments. Although PiB-PET imaging and CSF amyloid are the gold standards for early AD diagnosis, there are practical limitations for population screening. AD-related pathology occurs primarily in the brain, but some of the hallmarks of the disease have also been shown to occur in other tissues, including the retina, which is more accessible for imaging. Retinal vascular changes and degeneration have previously been reported in AD using optical coherence tomography and laser Doppler techniques. This report presents results from analysis of retinal photographs from AD and healthy control participants from the Australian Imaging, Biomarkers and Lifestyle (AIBL) Flagship Study of Ageing. This is the first study to investigate retinal blood vessel changes with respect to amyloid plaque burden in the brain. We demonstrate relationships between retinal vascular parameters, neocortical brain amyloid plaque burden and AD. A number of RVPs were found to be different in AD. Two of these RVPs, venular branching asymmetry factor and arteriolar length-to-diameter ratio, were also higher in healthy individuals with high plaque burden (P=0.01 and P=0.02 respectively, after false discovery rate adjustment). Retinal photographic analysis shows potential as an adjunct for early detection of AD or monitoring of AD-progression or response to treatments. PMID:23443359

  1. RNAi targeting multiple cell adhesion molecules reduces immune cell recruitment and vascular inflammation after myocardial infarction.

    PubMed

    Sager, Hendrik B; Dutta, Partha; Dahlman, James E; Hulsmans, Maarten; Courties, Gabriel; Sun, Yuan; Heidt, Timo; Vinegoni, Claudio; Borodovsky, Anna; Fitzgerald, Kevin; Wojtkiewicz, Gregory R; Iwamoto, Yoshiko; Tricot, Benoit; Khan, Omar F; Kauffman, Kevin J; Xing, Yiping; Shaw, Taylor E; Libby, Peter; Langer, Robert; Weissleder, Ralph; Swirski, Filip K; Anderson, Daniel G; Nahrendorf, Matthias

    2016-06-01

    Myocardial infarction (MI) leads to a systemic surge of vascular inflammation in mice and humans, resulting in secondary ischemic complications and high mortality. We show that, in ApoE(-/-) mice with coronary ligation, increased sympathetic tone up-regulates not only hematopoietic leukocyte production but also plaque endothelial expression of adhesion molecules. To counteract the resulting arterial leukocyte recruitment, we developed nanoparticle-based RNA interference (RNAi) that effectively silences five key adhesion molecules. Simultaneously encapsulating small interfering RNA (siRNA)-targeting intercellular cell adhesion molecules 1 and 2 (Icam1 and Icam2), vascular cell adhesion molecule 1 (Vcam1), and E- and P-selectins (Sele and Selp) into polymeric endothelial-avid nanoparticles reduced post-MI neutrophil and monocyte recruitment into atherosclerotic lesions and decreased matrix-degrading plaque protease activity. Five-gene combination RNAi also curtailed leukocyte recruitment to ischemic myocardium. Therefore, targeted multigene silencing may prevent complications after acute MI. PMID:27280687

  2. Detection of person borne IEDs using multiple cooperative sensors

    NASA Astrophysics Data System (ADS)

    MacIntosh, Scott; Deming, Ross; Hansen, Thorkild; Kishan, Neel; Tang, Ling; Shea, Jing; Lang, Stephen

    2011-06-01

    The use of multiple cooperative sensors for the detection of person borne IEDs is investigated. The purpose of the effort is to evaluate the performance benefits of adding multiple sensor data streams into an aided threat detection algorithm, and a quantitative analysis of which sensor data combinations improve overall detection performance. Testing includes both mannequins and human subjects with simulated suicide bomb devices of various configurations, materials, sizes and metal content. Aided threat recognition algorithms are being developed to test detection performance of individual sensors against combined fused sensors inputs. Sensors investigated include active and passive millimeter wave imaging systems, passive infrared, 3-D profiling sensors and acoustic imaging. The paper describes the experimental set-up and outlines the methodology behind a decision fusion algorithm-based on the concept of a "body model".

  3. In Vivo Detection of Vascular Adhesion Protein-1 in Experimental Inflammation

    PubMed Central

    Jaakkola, Kimmo; Nikula, Tuomo; Holopainen, Riikka; Vähäsilta, Tommi; Matikainen, Marja-Terttu; Laukkanen, Marja-Leena; Huupponen, Risto; Halkola, Lauri; Nieminen, Lauri; Hiltunen, Jukka; Parviainen, Sakari; Clark, Michael R.; Knuuti, Juhani; Savunen, Timo; Kääpä, Pekka; Voipio-Pulkki, Liisa Maria; Jalkanen, Sirpa

    2000-01-01

    Vascular adhesion protein-1 (VAP-1) is an inflammation-inducible endothelial glycoprotein which mediates leukocyte-endothelial cell interactions. To study the pathogenetic significance of VAP-1 in inflammatory disorders, an in vivo immunodetection method was used to detect the regulation of luminally expressed VAP-1 in experimental skin and joint inflammation in the pig and dog. Moreover, VAP-1 was studied as a potential target to localize inflammation by radioimmunoscintigraphy. Up-regulation of VAP-1 in experimental dermatitis and arthritis could be visualized by specifically targeted immunoscintigraphy. Moreover, the translocation of VAP-1 to the functional position on the endothelial surface was only seen in inflamed tissues. These results suggest that VAP-1 is both an optimal candidate for anti-adhesive therapy and a potential target molecule for imaging inflammation. PMID:10934150

  4. Accuracy of reflectance photoplethysmography on detecting cuff-induced vascular occlusions.

    PubMed

    Abay, T Y; Kyriacou, P A

    2015-08-01

    Photoplethysmography (PPG) is a noninvasive optical technique, which can also be used to derive important parameters other than arterial oxygen saturation (SpO2). In this work, the accuracy of the technique on detecting changes in blood perfusion during different levels of vascular occlusions has been explored. A dual-wavelength, reflectance PPG probe was applied on the left forearm of 10 healthy volunteers and raw PPG signals were acquired by a research PPG processing system. The raw PPG signals were separated into pulsatile AC and continuous DC PPG components. The signals were used to estimate SpO2 and changes in concentration of oxygenated, deoxygenated, and total haemoglobin. Different levels of occlusions, from 20 mmHg to total occlusion were induced by a pressure-cuff on the left arm. The system was able to indicate all the occlusions. In particular, the haemoglobin concentration changes estimated from PPG were in high agreement with Near Infrared Spectroscopy measurements. PMID:26736398

  5. Detection of a vascular permeability factor in the extracellular products of Renibacterium salmoninarum.

    PubMed

    Bandín, I; Santos, Y; Toranzo, A E; Barja, J L

    1992-09-01

    The presence of vascular permeability factors in the extracellular products (ECP) of 10 strains of Renibacterium salmoninarum with different geographical origin and serological characteristics are reported. All the ECP produced haemorrhagic and/or oedematous zones at the injection site with a diameter ranging from 10-30 mm. However, the ECP samples did not display toxic effect in fish at the same dose as inoculated in rabbit (180-400 micrograms protein/0.1 ml). No differences were observed in the production of this dermatotoxic factor between the two antigenic groups found in this microorganism. Whereas heating (80 and 100 degrees C/15 min) the ECP samples resulted in a complete loss of their proteolytic activity, only a decrease (but not total inactivation) of the dermatotoxic effects was detected. Therefore, although proteases could be implicated in the permeability factor, they are not totally responsible for this activity. PMID:1291845

  6. Coherent control of multiple vibrational excitations for optimal detection

    NASA Astrophysics Data System (ADS)

    McGrane, S. D.; Scharff, R. J.; Greenfield, M.; Moore, D. S.

    2009-10-01

    While the means to selectively excite a single vibrational mode using ultrafast pulse shaping are well established, the subsequent problem of selectively exciting multiple vibrational modes simultaneously has been largely neglected. The coherent control of multiple vibrational excitations has applications in control of chemistry, chemical detection and molecular vibrational quantum information processing. Using simulations and experiments, we demonstrate that multiple vibrational modes can be selectively excited with the concurrent suppression of multiple interfering modes by orders of magnitude. While the mechanism of selectivity is analogous to that of single mode selectivity, the interferences required to select multiple modes require complicated non-intuitive pulse trains. Additionally, we show that selective detection can be achieved by the optimal pulse shape, even when the nature of the interfering species is varied, suggesting that optimized detection should be practical in real world applications. Experimental measurements of the multiplex coherent anti-Stokes Raman spectra (CARS) and CARS decay times of toluene, acetone, cis-stilbene and nitromethane liquids are reported, along with optimizations attempting to selectively excite nitromethane in a mixture of the four solvents. The experimental implementation exhibits a smaller degree of signal to background enhancement than predicted, which is primarily attributed to the single objective optimization methodology and not to fundamental limitations.

  7. Detecting multiple adulterants in dry milk using Raman chemical imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Raman chemical imaging method was developed for detecting the presence of multiple chemical adulterants in dry milk powder. Four chemicals (ammonium sulfate, dicyandiamide, melamine, and urea) were added in equal concentrations, between 0.1% and 5.0%, to nonfat dry milk. An area of 25×25 mm2 for e...

  8. Embolization of a giant arterioportal fistula requiring multiple Amplatzer vascular plugs.

    PubMed

    Ward, Thomas J; Marin, Michael L; Lookstein, Robert A

    2015-12-01

    Arterioportal fistulas (APFs) are rare vascular communications between the mesenteric arterial tree and the portal vein. The causes and presentations of this entity are varied. APFs related to tumor, infection, and trauma have been described. Patients may be asymptomatic or present with hemobilia, portal hypertension, or mesenteric steal syndrome. Small APFs require no intervention, with treatment indicated for large or symptomatic APFs. The treatment has shifted from surgical ligation or hepatic resection to an endovascular-first approach. We describe an endovascular treatment option for the management of an acquired extrahepatic (type 2) APF and present a review of the literature. PMID:24840744

  9. Breast Contrast Enhanced MR Imaging: Semi-Automatic Detection of Vascular Map and Predominant Feeding Vessel

    PubMed Central

    Petrillo, Antonella; Fusco, Roberta; Filice, Salvatore; Granata, Vincenza; Catalano, Orlando; Vallone, Paolo; Di Bonito, Maurizio; D’Aiuto, Massimiliano; Rinaldo, Massimo; Capasso, Immacolata; Sansone, Mario

    2016-01-01

    Purpose To obtain breast vascular map and to assess correlation between predominant feeding vessel and tumor location with a semi-automatic method compared to conventional radiologic reading. Methods 148 malignant and 75 benign breast lesions were included. All patients underwent bilateral MR imaging. Written informed consent was obtained from the patients before MRI. The local ethics committee granted approval for this study. Semi-automatic breast vascular map and predominant vessel detection was performed on MRI, for each patient. Semi-automatic detection (depending on grey levels threshold manually chosen by radiologist) was compared with results of two expert radiologists; inter-observer variability and reliability of semi-automatic approach were assessed. Results Anatomic analysis of breast lesions revealed that 20% of patients had masses in internal half, 50% in external half and the 30% in subareolar/central area. As regards the 44 tumors in internal half, based on radiologic consensus, 40 demonstrated a predominant feeding vessel (61% were supplied by internal thoracic vessels, 14% by lateral thoracic vessels, 16% by both thoracic vessels and 9% had no predominant feeding vessel—p<0.01), based on semi-automatic detection, 38 tumors demonstrated a predominant feeding vessel (66% were supplied by internal thoracic vessels, 11% by lateral thoracic vessels, 9% by both thoracic vessels and 14% had no predominant feeding vessel—p<0.01). As regards the 111 tumors in external half, based on radiologic consensus, 91 demonstrated a predominant feeding vessel (25% were supplied by internal thoracic vessels, 39% by lateral thoracic vessels, 18% by both thoracic vessels and 18% had no predominant feeding vessel—p<0.01), based on semi-automatic detection, 94 demonstrated a predominant feeding vessel (27% were supplied by internal thoracic vessels, 45% by lateral thoracic vessels, 4% by both thoracic vessels and 24% had no predominant feeding vessel—p<0.01). An

  10. Detection of Biological Pathogens Using Multiple Wireless Magnetoelastic Biosensors

    NASA Astrophysics Data System (ADS)

    Shen, Wen

    A number of recent, high-profile incidences of food-borne illness spreading through the food supply and the use of anthrax by terrorists after the September 11, 2001 attacks have demonstrated the need for new technologies that can rapidly detect the presence of biological pathogens. A bevy of biosensors show excellent detection sensitivity and specificity. However, false positive and false negative signals remain one of the primary reasons that many of these newly developed biosensors have not found application in the marketplace. The research described in this dissertation focuses on developing a free-standing magnetoelastic based bio-sensing system using a pulse method. This method allows fast detection, eliminates the bias magnetic field that is necessary in current methods, makes the system more simply and suitable for in-field detection. This system has two pairs of transformer coils, where a measurement sensor and a control sensor can be put in each pair of coils. The control sensor is used to compensate for environmental variables. The effect of pulse power on the performance of the magnetoelastic sensors in the pulse system is studied. The system is found to have excellent stability, good detection repeatability when used with multiple sensors. This research has investigated and demonstrated a multiple sensors approach. Because it will involve the simultaneous measurement of many sensors, it will significantly reduce problems encountered with false positive indications. The positioning and interference of sensors are investigated. By adding a multi-channel structure to the pulse detection system, the effect of sensor interference is minimized. The result of the repeatability test shows that the standard deviation when measuring three 1 mm magnetoelastic sensors is around 500 Hz, which is smaller than the minimum requirement for actual spores/bacteria detection. Magnetoelastic sensors immobilized with JRB7 phages and E2 phages have been used to specifically

  11. Neuronal Nitric Oxide Synthase is Involved in Vascular Hyporeactivity and Multiple Organ Dysfunction Associated with Hemorrhagic Shock.

    PubMed

    Sordi, Regina; Chiazza, Fausto; Collino, Massimo; Assreuy, Jamil; Thiemermann, Christoph

    2016-05-01

    Severe hemorrhage can lead to global ischemia and hemorrhagic shock (HS), resulting in multiple organ failure (MOF) and death. Restoration of blood flow and re-oxygenation is associated with an exacerbation of tissue injury and inflammatory response. The neuronal nitric oxide synthase (nNOS) has been implicated in vascular collapse and systemic inflammation of septic shock; however, the role of nNOS in HS is poorly understood. The aim of this study was to evaluate the role of nNOS in the MOF associated with HS.Rats were subjected to HS under anesthesia. Mean arterial pressure was reduced to 30 mmHg for 90 min, followed by resuscitation with shed blood. Rats were randomly treated with two chemically distinct nNOS inhibitors [ARL 17477 (1 mg/kg) and 7-nitroindazol (5 mg/kg)] or vehicle upon resuscitation. Four hours later, parameters of organ injury and dysfunction were assessed.HS was associated with MOF development. Inhibition of nNOS activity at resuscitation protected rats against the MOF and vascular dysfunction. In addition, treatment of HS rats with nNOS inhibitors attenuated neutrophil infiltration into target organs and decreased the activation of NF-κB, iNOS expression, NO production, and nitrosylation of proteins. Furthermore, nNOS inhibition also reduced the levels of pro-inflammatory cytokines TNF-α and IL-6 in HS rats.In conclusion, two distinct inhibitors of nNOS activity reduced the MOF, vascular dysfunction, and the systemic inflammation associated with HS. Thus, nNOS inhibitors may be useful as an adjunct therapy before fluids and blood administration in HS patients to avoid the MOF associated with reperfusion injury during resuscitation. PMID:26863124

  12. The Notch Ligand Delta-Like 4 Regulates Multiple Stages of Early Hemato-Vascular Development

    PubMed Central

    Neves, Hélia; Gomes, Andreia C.; Saavedra, Pedro; Carvalho, Catarina C.; Duarte, António; Cidadão, António; Parreira, Leonor

    2012-01-01

    Background In mouse embryos, homozygous or heterozygous deletions of the gene encoding the Notch ligand Dll4 result in early embryonic death due to major defects in endothelial remodeling in the yolk sac and embryo. Considering the close developmental relationship between endothelial and hematopoietic cell lineages, which share a common mesoderm-derived precursor, the hemangioblast, and many key regulatory molecules, we investigated whether Dll4 is also involved in the regulation of early embryonic hematopoiesis. Methodology/Principal Findings Using Embryoid Bodies (EBs) derived from embryonic stem cells harboring hetero- or homozygous Dll4 deletions, we observed that EBs from both genotypes exhibit an abnormal endothelial remodeling in the vascular sprouts that arise late during EB differentiation, indicating that this in vitro system recapitulates the angiogenic phenotype of Dll4 mutant embryos. However, analysis of EB development at early time points revealed that the absence of Dll4 delays the emergence of mesoderm and severely reduces the number of blast-colony forming cells (BL-CFCs), the in vitro counterpart of the hemangioblast, and of endothelial cells. Analysis of colony forming units (CFU) in EBs and yolk sacs from Dll4+/− and Dll4−/− embryos, showed that primitive erythropoiesis is specifically affected by Dll4 insufficiency. In Dll4 mutant EBs, smooth muscle cells (SMCs) were seemingly unaffected and cardiomyocyte differentiation was increased, indicating that SMC specification is Dll4-independent while a normal dose of this Notch ligand is essential for the quantitative regulation of cardiomyogenesis. Conclusions/Significance This study highlights a previously unnoticed role for Dll4 in the quantitative regulation of early hemato-vascular precursors, further indicating that it is also involved on the timely emergence of mesoderm in early embryogenesis. PMID:22514637

  13. Detection of familial adenomatous polyposis with polarized spectroscopic imaging and oral vascular density

    NASA Astrophysics Data System (ADS)

    Basiri, Ali; Edelstein, Daniel L.; Giardiello, Francis M.; Ramella-Roman, J. C.

    2011-03-01

    Familial Adenomatous Polyposis (FAP) is an autosomal dominant disease characterized by the development of multiple colonic polyps at younger age with a near 100% lifetime risk of colorectal cancer in later years. The determination of FAP is made after extensive clinical evaluation and genetic testing of at risk individuals. Genetic testing is expensive and in some cases deleterious mutations are not found in all patients with a clinical diagnosis of FAP. As such, the early identification of affected individuals could substantially eliminate associated morbidity and mortality. We investigated a novel spectro-polarimetric imaging system to capture images of the oral mucosa at different wavelengths in an attempt to distinguish patients with FAP from controls. Total diffused oral mucosal reflectance (OMR) and oral mucosal vascular density (OMVD) were calculated from spectral data collected from 33 patients with gene positive FAP, 5 patients who tested negative for FAP, and 45 controls. A statistically significant difference in OMVD (p < 0.001) was observed between individuals with FAP and controls. Analysis of OMR showed no significant difference between the two subject groups.

  14. Multiple-Beam Detection of Fast Transient Radio Sources

    NASA Technical Reports Server (NTRS)

    Thompson, David R.; Wagstaff, Kiri L.; Majid, Walid A.

    2011-01-01

    A method has been designed for using multiple independent stations to discriminate fast transient radio sources from local anomalies, such as antenna noise or radio frequency interference (RFI). This can improve the sensitivity of incoherent detection for geographically separated stations such as the very long baseline array (VLBA), the future square kilometer array (SKA), or any other coincident observations by multiple separated receivers. The transients are short, broadband pulses of radio energy, often just a few milliseconds long, emitted by a variety of exotic astronomical phenomena. They generally represent rare, high-energy events making them of great scientific value. For RFI-robust adaptive detection of transients, using multiple stations, a family of algorithms has been developed. The technique exploits the fact that the separated stations constitute statistically independent samples of the target. This can be used to adaptively ignore RFI events for superior sensitivity. If the antenna signals are independent and identically distributed (IID), then RFI events are simply outlier data points that can be removed through robust estimation such as a trimmed or Winsorized estimator. The alternative "trimmed" estimator is considered, which excises the strongest n signals from the list of short-beamed intensities. Because local RFI is independent at each antenna, this interference is unlikely to occur at many antennas on the same step. Trimming the strongest signals provides robustness to RFI that can theoretically outperform even the detection performance of the same number of antennas at a single site. This algorithm requires sorting the signals at each time step and dispersion measure, an operation that is computationally tractable for existing array sizes. An alternative uses the various stations to form an ensemble estimate of the conditional density function (CDF) evaluated at each time step. Both methods outperform standard detection strategies on a test

  15. Automatic detection of pelvic lymph nodes using multiple MR sequences

    NASA Astrophysics Data System (ADS)

    Yan, Michelle; Lu, Yue; Lu, Renzhi; Requardt, Martin; Moeller, Thomas; Takahashi, Satoru; Barentsz, Jelle

    2007-03-01

    A system for automatic detection of pelvic lymph nodes is developed by incorporating complementary information extracted from multiple MR sequences. A single MR sequence lacks sufficient diagnostic information for lymph node localization and staging. Correct diagnosis often requires input from multiple complementary sequences which makes manual detection of lymph nodes very labor intensive. Small lymph nodes are often missed even by highly-trained radiologists. The proposed system is aimed at assisting radiologists in finding lymph nodes faster and more accurately. To the best of our knowledge, this is the first such system reported in the literature. A 3-dimensional (3D) MR angiography (MRA) image is employed for extracting blood vessels that serve as a guide in searching for pelvic lymph nodes. Segmentation, shape and location analysis of potential lymph nodes are then performed using a high resolution 3D T1-weighted VIBE (T1-vibe) MR sequence acquired by Siemens 3T scanner. An optional contrast-agent enhanced MR image, such as post ferumoxtran-10 T2*-weighted MEDIC sequence, can also be incorporated to further improve detection accuracy of malignant nodes. The system outputs a list of potential lymph node locations that are overlaid onto the corresponding MR sequences and presents them to users with associated confidence levels as well as their sizes and lengths in each axis. Preliminary studies demonstrates the feasibility of automatic lymph node detection and scenarios in which this system may be used to assist radiologists in diagnosis and reporting.

  16. Detecting Vascular-Targeting Effects of the Hypoxic Cytotoxin Tirapazamine in Tumor Xenografts Using Magnetic Resonance Imaging

    SciTech Connect

    Bains, Lauren J.; Baker, Jennifer; Kyle, Alastair H.; Minchinton, Andrew I.; Reinsberg, Stefan A.

    2009-07-01

    Purpose: To determine whether vascular-targeting effects can be detected in vivo using magnetic resonance imaging (MRI). Methods and Materials: MR images of HCT-116 xenograft-bearing mice were acquired at 7 Tesla before and 24 hours after intraperitoneal injections of tirapazamine. Quantitative dynamic contrast-enhanced MRI analyses were performed to evaluate changes in tumor perfusion using two biomarkers: the volume transfer constant (K{sup trans}) and the initial area under the concentration-time curve (IAUC). We used novel implanted fiducial markers to obtain cryosections that corresponded to MR image planes from excised tumors; quantitative immunohistochemical mapping of tumor vasculature, perfusion, and necrosis enabled correlative analysis between these and MR images. Results: Conventional histological analysis showed lower vascular perfusion or greater amounts of necrosis in the central regions of five of eight tirapazamine-treated tumors, with three treated tumors showing no vascular dysfunction response. MRI data reflected this result, and a striking decrease in both K{sup trans} and IAUC values was seen with the responsive tumors. Retrospective evaluation of pretreatment MRI parameters revealed that those tumors that did not respond to the vascular-targeting effects of tirapazamine had significantly higher pretreatment K{sup trans} and IAUC values. Conclusions: MRI-derived parameter maps showed good agreement with histological tumor mapping. MRI was found to be an effective tool for noninvasively monitoring and predicting tirapazamine-mediated central vascular dysfunction.

  17. Optimum testing of multiple hypotheses in quantum detection theory

    NASA Technical Reports Server (NTRS)

    Yuen, H. P.; Kennedy, R. S.; Lax, M.

    1975-01-01

    The problem of specifying the optimum quantum detector in multiple hypotheses testing is considered for application to optical communications. The quantum digital detection problem is formulated as a linear programming problem on an infinite-dimensional space. A necessary and sufficient condition is derived by the application of a general duality theorem specifying the optimum detector in terms of a set of linear operator equations and inequalities. Existence of the optimum quantum detector is also established. The optimality of commuting detection operators is discussed in some examples. The structure and performance of the optimal receiver are derived for the quantum detection of narrow-band coherent orthogonal and simplex signals. It is shown that modal photon counting is asymptotically optimum in the limit of a large signaling alphabet and that the capacity goes to infinity in the absence of a bandwidth limitation.

  18. Gold nanoparticle modified capacitive sensor platform for multiple marker detection.

    PubMed

    Altintas, Zeynep; Kallempudi, Sreenivasa Saravan; Gurbuz, Yasar

    2014-01-01

    The detection and quantification of cancer biomarkers in human blood is crucial to diagnose patients in the early stage of a disease. The recent advances in biosensor technology can improve detection by reducing the application time and cost without an invasive approach. In this study, a highly sensitive, novel nanoparticle-modified capacitive sensor was developed for the detection of cancer markers. The current work mainly focused on developing a surface modification protocol for achieving higher sensitivity using Au-NPs. An interdigitated electrode (IDE) transducer was modified using gold nanoparticles (Au-NPs) for signal enhancement, the platform was initially optimized with a small size IL-6 protein and the methodology was then applied for multiple marker detection with the aim of precise disease diagnostics. Carcinoembryonic antigen (CEA) and epidermal growth factor receptor (hEGFR) could be successfully detected in the concentration range of 20-1000 pg mL(-1) while cancer antigen 15-3 (CA15-3) was detected in the range of 10-200 U mL(-1). These results show an increase of sensitivity by five-fold with respect to those not modified, demonstrating a highly sensitive and specific capacitive immunoassay that has a great potential for the use of early diagnosis of cancer disease. PMID:24274298

  19. Detection method for dissociation of multiple-charged ions

    DOEpatents

    Smith, Richard D.; Udseth, Harold R.; Rockwood, Alan L.

    1991-01-01

    Dissociations of multiple-charged ions are detected and analyzed by charge-separation tandem mass spectrometry. Analyte molecules are ionized to form multiple-charged parent ions. A particular charge parent ion state is selected in a first-stage mass spectrometer and its mass-to-charge ratio (M/Z) is detected to determine its mass and charge. The selected parent ions are then dissociated, each into a plurality of fragments including a set of daughter ions each having a mass of at least one molecular weight and a charge of at least one. Sets of daughter ions resulting from the dissociation of one parent ion (sibling ions) vary in number but typically include two to four ions, one or more multiply-charged. A second stage mass spectrometer detects mass-to-charge ratio (m/z) of the daughter ions and a temporal or temporo-spatial relationship among them. This relationship is used to correlate the daughter ions to determine which (m/z) ratios belong to a set of sibling ions. Values of mass and charge of each of the sibling ions are determined simultaneously from their respective (m/z) ratios such that the sibling ion charges are integers and sum to the parent ion charge.

  20. Optimal seamline detection for multiple image mosaicking via graph cuts

    NASA Astrophysics Data System (ADS)

    Li, Li; Yao, Jian; Lu, Xiaohu; Tu, Jinge; Shan, Jie

    2016-03-01

    While mosaicking images, especially captured from the scenes of large depth differences with respective to cameras at varying locations, the detection of seamlines within overlap regions is a key issue for creating seamless and pleasant image mosaics. In this paper, we propose a novel algorithm to efficiently detect optimal seamlines for mosaicking aerial images captured from different viewpoints and for mosaicking street-view panoramic images without a precisely common center in a graph cuts energy minimization framework. To effectively ensure that the seamlines are optimally detected in the laterally continuous regions with high image similarity and low object dislocation to magnificently conceal the parallax between images, we fuse the information of image color, gradient magnitude, and texture complexity into the data and smooth energy terms in graph cuts. Different from the traditional frame-to-frame optimization for sequentially detecting seamlines for mosaicking multiple images, our method applies a novel multi-frame joint optimization strategy to find seamlines within multi-overlapped images at one time. In addition, we propose simple but effective strategies to semi-automatically guide the seamlines by exploiting simple human-computer interaction strongly constraining the image regions that the seamlines will or won't pass through, which is often ignored by many existing seamline detection methods. Experimental results on a large set of aerial, oblique and street-view panoramic images show that the proposed method is capable of creating high-quality seamlines for multiple image mosaicking, while not crossing majority of visually obvious foreground objects and most of overlap regions with low image similarity to effectively conceal the image parallax at different extents.

  1. Detecting resting-state brain activity by spontaneous cerebral blood volume fluctuations using whole brain vascular space occupancy imaging.

    PubMed

    Miao, Xinyuan; Gu, Hong; Yan, Lirong; Lu, Hanzhang; Wang, Danny J J; Zhou, Xiaohong Joe; Zhuo, Yan; Yang, Yihong

    2014-01-01

    Resting-state brain activity has been investigated extensively using BOLD contrast. However, BOLD signal represents the combined effects of multiple physiological processes and its spatial localization is less accurate than that of cerebral blood flow and volume (CBF and CBF, respectively). In this study, we demonstrate that resting-state brain activity can be reliably detected by spontaneous fluctuations of CBV-weighted signal using whole-brain gradient and spin echo (GRASE) based vascular space occupancy (VASO) imaging. Specifically, using independent component analysis, intrinsic brain networks, including default mode, salience, executive control, visual, auditory, and sensorimotor networks were revealed robustly by the VASO technique. We further demonstrate that task-evoked VASO signal aligned well with expected gray matter areas, while blood-oxygenation level dependent (BOLD) signal extended outside of these areas probably due to their different spatial specificity. The improved spatial localization of VASO is consistent with previous studies using animal models. Moreover, we showed that the 3D-GRASE VASO images had reduced susceptibility-induced signal voiding, compared to the BOLD technique. This is attributed to the fact that VASO does not require T2* weighting, thus the acquisition can use a shorter TE and can employ spin-echo scheme. Consequently VASO-based functional connectivity signals were well preserved in brain regions that tend to suffer from signal loss and geometric distortion in BOLD, such as orbital prefrontal cortex. Our study suggests that 3D-GRASE VASO imaging, with its improved spatial specificity and less sensitivity to susceptibility artifacts, may have advantages in resting-state fMRI studies. PMID:24055705

  2. Detection of electromagnetic radiation using micromechanical multiple quantum wells structures

    DOEpatents

    Datskos, Panagiotis G [Knoxville, TN; Rajic, Slobodan [Knoxville, TN; Datskou, Irene [Knoxville, TN

    2007-07-17

    An apparatus and method for detecting electromagnetic radiation employs a deflectable micromechanical apparatus incorporating multiple quantum wells structures. When photons strike the quantum-well structure, physical stresses are created within the sensor, similar to a "bimetallic effect." The stresses cause the sensor to bend. The extent of deflection of the sensor can be measured through any of a variety of conventional means to provide a measurement of the photons striking the sensor. A large number of such sensors can be arranged in a two-dimensional array to provide imaging capability.

  3. Estimation and detection of signals in multiplicative noise

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.

    1973-01-01

    A class of detection-estimation problems on matrix Lie groups is defined in which the observation noise is multiplicative in nature. By examining the differential versions of the hypotheses, which are bilinear in nature, it is possible to derive the relevant likelihood ratio formula and the associated optimal estimation equations for the signal given the observations and the assumption that the signal is present. These estimation equations are of interest in their own right, in that they represent a finite dimensional optimal solution to a nonlinear estimation problem and can be viewed as consisting of a Kalman-Bucy filter along with the on-line computation of the solution of the associated Riccati equation, which is driven by the observations. The usefulness of these results is illustrated via an example concerning the detection of an actuator failure in a rigid body rotational control system.

  4. Estimation and detection of signals in multiplicative noise

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.

    1974-01-01

    We define a class of detection-estimation problems on matrix Lie groups in which the observation noise is multiplicative in nature. By examining the differential versions of the hypotheses, which are bilinear, we are able to derive the relevant likelihood ratio formula and the associated optimal estimation equations for the signal given the observations and the assumption that the signal is present. These estimation equations are of interest in their own right, in that they represent a finite-dimensional optimal solution to a nonlinear estimation problem and consist of a Kalman-Bucy filter along with the on-line computation of the solution of the associated Riccati equation, which is driven by the observations. The usefulness of these results is illustrated via an example concerning the detection of an actuator failure in a rigid-body rotational control system.

  5. A novel interacting multiple model based network intrusion detection scheme

    NASA Astrophysics Data System (ADS)

    Xin, Ruichi; Venkatasubramanian, Vijay; Leung, Henry

    2006-04-01

    In today's information age, information and network security are of primary importance to any organization. Network intrusion is a serious threat to security of computers and data networks. In internet protocol (IP) based network, intrusions originate in different kinds of packets/messages contained in the open system interconnection (OSI) layer 3 or higher layers. Network intrusion detection and prevention systems observe the layer 3 packets (or layer 4 to 7 messages) to screen for intrusions and security threats. Signature based methods use a pre-existing database that document intrusion patterns as perceived in the layer 3 to 7 protocol traffics and match the incoming traffic for potential intrusion attacks. Alternately, network traffic data can be modeled and any huge anomaly from the established traffic pattern can be detected as network intrusion. The latter method, also known as anomaly based detection is gaining popularity for its versatility in learning new patterns and discovering new attacks. It is apparent that for a reliable performance, an accurate model of the network data needs to be established. In this paper, we illustrate using collected data that network traffic is seldom stationary. We propose the use of multiple models to accurately represent the traffic data. The improvement in reliability of the proposed model is verified by measuring the detection and false alarm rates on several datasets.

  6. Improving performance of computer-aided detection of pulmonary embolisms by incorporating a new pulmonary vascular-tree segmentation algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Xingwei; Song, XiaoFei; Chapman, Brian E.; Zheng, Bin

    2012-03-01

    We developed a new pulmonary vascular tree segmentation/extraction algorithm. The purpose of this study was to assess whether adding this new algorithm to our previously developed computer-aided detection (CAD) scheme of pulmonary embolism (PE) could improve the CAD performance (in particular reducing false positive detection rates). A dataset containing 12 CT examinations with 384 verified pulmonary embolism regions associated with 24 threedimensional (3-D) PE lesions was selected in this study. Our new CAD scheme includes the following image processing and feature classification steps. (1) A 3-D based region growing process followed by a rolling-ball algorithm was utilized to segment lung areas. (2) The complete pulmonary vascular trees were extracted by combining two approaches of using an intensity-based region growing to extract the larger vessels and a vessel enhancement filtering to extract the smaller vessel structures. (3) A toboggan algorithm was implemented to identify suspicious PE candidates in segmented lung or vessel area. (4) A three layer artificial neural network (ANN) with the topology 27-10-1 was developed to reduce false positive detections. (5) A k-nearest neighbor (KNN) classifier optimized by a genetic algorithm was used to compute detection scores for the PE candidates. (6) A grouping scoring method was designed to detect the final PE lesions in three dimensions. The study showed that integrating the pulmonary vascular tree extraction algorithm into the CAD scheme reduced false positive rates by 16.2%. For the case based 3D PE lesion detecting results, the integrated CAD scheme achieved 62.5% detection sensitivity with 17.1 false-positive lesions per examination.

  7. Multiple Coherence vs Multiple Component Synchrony Measure for somatosensory evoked response detection.

    PubMed

    Melges, Danilo B; Miranda de Sa, Antonio Mauricio F L; Infantosi, Antonio Fernando C

    2010-01-01

    This work aims at comparing the performance of two Multivariate Objective Response Detection (MORD) techniques in the frequency domain, the Multiple Coherence (MC) and the Multiple Component Synchrony Measure (MCSM), for tibial nerve somatosensory evoked potential (SEP) detection. Electroencephalographic (EEG) signals during somatosensory stimulation were collected from forty adult volunteers using the 10-20 International System. The stimulation was carried out throughout current pulses (200 µs width) applied to the right posterior tibial nerve (motor threshold intensity level) at the rate of 5 Hz. The response detection was based on rejecting the null hypothesis of response absence (M = 100 and M = 800 epochs and significance level α = 0.05). The MORD techniques were applied to the pairs of derivations [Cz][Fz] and [C3][C4]. The MC outperforms the MCSM, regardless the pair of derivations or the number of epochs used for the estimates calculation. Hence, the MC should be used, if two derivations are available for SEP recording. PMID:21096391

  8. Multiple instance learning for landmine detection using ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Manandhar, Achut; Morton, Kenneth D., Jr.; Collins, Leslie M.; Torrione, Peter A.

    2012-06-01

    Ground Penetrating Radar (GPR) has been extensively employed as a technology for the detection of subsurface buried threats. Although vehicular mounted GPRs generate data in three dimensions, alarm declarations are usually only available in the form of 2-D spatial coordinates. The uncertainty in the depth of the target in the three dimensional volume of data, and the difficulties associated with automatically localizing objects in depth, can adversely impact feature extraction and training in some detection algorithms. In order to mitigate the negative impact of uncertainty in target depth, several algorithms have been developed that extract features from multiple depth regions and utilize these feature vectors in classification algorithms to perform final mine/nonmine decisions. However, the uncertainty in object depth significantly complicates learning since features at the correct target depth are often significantly different from features at other depths but in the same volume. Multiple Instance Learning (MIL) is a type of supervised learning approach in which labels are available for a collection of feature vectors but not for individual samples, or in this application, depths. The goal of MIL is to classify new collections of vectors as they become available. This set-based learning method is applicable in the landmine detection problem because features that are extracted independently from several depth bins can be viewed as a set of unlabeled feature vectors, where the entire set either corresponds to a buried threat or a false alarm. In this work, a novel generative Dirichlet Process Gaussian mixture model for MIL is developed that automatically infers the number of mixture components required to model the underlying distributions of mine/non-mine signatures and performs classification using a likelihood ratio test. In this work, we show that the performance of the proposed approach for discriminating targets from non-targets in GPR data is promising.

  9. Detection of biogenic CO production above vascular cell cultures using a near-room-temperature QC-DFB laser

    NASA Technical Reports Server (NTRS)

    Kosterev, A. A.; Tittel, F. K.; Durante, W.; Allen, M.; Kohler, R.; Gmachl, C.; Capasso, F.; Sivco, D. L.; Cho, A. Y.

    2002-01-01

    We report the first application of pulsed, near-room-temperature quantum cascade laser technology to the continuous detection of biogenic CO production rates above viable cultures of vascular smooth muscle cells. A computer-controlled sequence of measurements over a 9-h period was obtained, resulting in a minimum detectable CO production of 20 ppb in a 1-m optical path above a standard cell-culture flask. Data-processing procedures for real-time monitoring of both biogenic and ambient atmospheric CO concentrations are described.

  10. Multiple-Instance Learning for Anomaly Detection in Digital Mammography.

    PubMed

    Quellec, Gwenole; Lamard, Mathieu; Cozic, Michel; Coatrieux, Gouenou; Cazuguel, Guy

    2016-07-01

    This paper describes a computer-aided detection and diagnosis system for breast cancer, the most common form of cancer among women, using mammography. The system relies on the Multiple-Instance Learning (MIL) paradigm, which has proven useful for medical decision support in previous works from our team. In the proposed framework, breasts are first partitioned adaptively into regions. Then, features derived from the detection of lesions (masses and microcalcifications) as well as textural features, are extracted from each region and combined in order to classify mammography examinations as "normal" or "abnormal". Whenever an abnormal examination record is detected, the regions that induced that automated diagnosis can be highlighted. Two strategies are evaluated to define this anomaly detector. In a first scenario, manual segmentations of lesions are used to train an SVM that assigns an anomaly index to each region; local anomaly indices are then combined into a global anomaly index. In a second scenario, the local and global anomaly detectors are trained simultaneously, without manual segmentations, using various MIL algorithms (DD, APR, mi-SVM, MI-SVM and MILBoost). Experiments on the DDSM dataset show that the second approach, which is only weakly-supervised, surprisingly outperforms the first approach, even though it is strongly-supervised. This suggests that anomaly detectors can be advantageously trained on large medical image archives, without the need for manual segmentation. PMID:26829783

  11. Biological impact of vascular endothelial growth factor on vessel density and survival in multiple myeloma and plasmacytoma.

    PubMed

    Swelam, Wael M; Al Tamimi, Dalal M

    2010-11-15

    We compared the differences in a number of angiogenesis-related immunohistochemical parameters, including microvascular density (MVD) and tumor cell activity, between multiple myeloma (MM) and solitary plasmacytoma (SP). Tissue sections from tumors of MM and SP were immunohistochemically stained and analyzed using ImageJ image analysis software for the expression of vascular endothelial growth factor (VEGF), VEGF receptors (Flt-1 and Flk-1), inducible nitric oxide (iNOS), and anti-apoptotic (Bcl-2) protein. Tumor tissues were cytologically graded as high-, intermediate-, or low-grade. Two pathologists determined the MVD of each section independently by recording the average number of CD34+ blood vessels in 500 unit fields. The arithmetic means for MVD were statistically analyzed using the Student's t-test and the significance level was calculated at P-value <0.001. The results indicate a direct correlation between upregulation of iNOS/VEGF in high-grade tumors. For MM, an increase in MVD is also correlated with a high-grade. Tumor survival signaling by Bcl-2 in both SP and MM emphasizes the fact that VEGF has a bimodal role that is mainly angiogenic in MM and tumorigenic, promoting tumor cell survival in SP. PMID:20709463

  12. Bayesian Minimum Description Length Techniques for Multiple Changepoint Detection

    NASA Astrophysics Data System (ADS)

    Anuradha Priyadarshani, Hewa Arachchige

    This dissertation develops a minimum description length (MDL) multiple changepoint detection procedure that allows for prior distributions. MDL methods, which are penalized likelihood techniques with penalties based on data description-length information principles, have been successfully applied to many recent multiple changepoint problems. This work shows how to modify the MDL penalty to account for various prior knowledge. Our motivation lies in climatology. Here, a metadata record, which is a file listing times when a recording station physically moved, instrumentation was changed, etc., sometimes exists. While metadata records are notoriously incomplete, they permit the construct a prior distribution that helps detect changepoints. This allows both documented and undocumented changepoints to be analyzed in tandem. The method developed here takes into account 1) metadata, 2) reference series, 3) seasonal means, and 4) autocorrelations. Asymptotically, our estimated multiple changepoint configuration of monthly data is shown to be consistent. The methods are illustrated in the analysis of 114 years of monthly temperatures from Tuscaloosa, Alabama. The multivariate aspect of the methods allow maximum and minimum temperatures to be jointly studied. A method for homogenizing daily temperature series is also developed. While daily temperatures have a complex structure, statistical techniques have been accumulating that can now accommodate all of the salient characteristics of daily temperatures. The goal here is to combine these techniques in a reasonable manner for multiple changepoint identification in daily series; computational speed is key as a century of daily data has over 36,000 data points. Autocorrelation aspects are important since correlation can destroy changepoint techniques and sample correlations of day-to-day temperature anomalies are often as large as 0.7. While homogenized daily temperatures may not be as useful as homogenized monthly or yearly

  13. Dynamic multiple thresholding breast boundary detection algorithm for mammograms

    SciTech Connect

    Wu, Yi-Ta; Zhou Chuan; Chan, Heang-Ping; Paramagul, Chintana; Hadjiiski, Lubomir M.; Daly, Caroline Plowden; Douglas, Julie A.; Zhang Yiheng; Sahiner, Berkman; Shi Jiazheng; Wei Jun

    2010-01-15

    Purpose: Automated detection of breast boundary is one of the fundamental steps for computer-aided analysis of mammograms. In this study, the authors developed a new dynamic multiple thresholding based breast boundary (MTBB) detection method for digitized mammograms. Methods: A large data set of 716 screen-film mammograms (442 CC view and 274 MLO view) obtained from consecutive cases of an Institutional Review Board approved project were used. An experienced breast radiologist manually traced the breast boundary on each digitized image using a graphical interface to provide a reference standard. The initial breast boundary (MTBB-Initial) was obtained by dynamically adapting the threshold to the gray level range in local regions of the breast periphery. The initial breast boundary was then refined by using gradient information from horizontal and vertical Sobel filtering to obtain the final breast boundary (MTBB-Final). The accuracy of the breast boundary detection algorithm was evaluated by comparison with the reference standard using three performance metrics: The Hausdorff distance (HDist), the average minimum Euclidean distance (AMinDist), and the area overlap measure (AOM). Results: In comparison with the authors' previously developed gradient-based breast boundary (GBB) algorithm, it was found that 68%, 85%, and 94% of images had HDist errors less than 6 pixels (4.8 mm) for GBB, MTBB-Initial, and MTBB-Final, respectively. 89%, 90%, and 96% of images had AMinDist errors less than 1.5 pixels (1.2 mm) for GBB, MTBB-Initial, and MTBB-Final, respectively. 96%, 98%, and 99% of images had AOM values larger than 0.9 for GBB, MTBB-Initial, and MTBB-Final, respectively. The improvement by the MTBB-Final method was statistically significant for all the evaluation measures by the Wilcoxon signed rank test (p<0.0001). Conclusions: The MTBB approach that combined dynamic multiple thresholding and gradient information provided better performance than the breast boundary

  14. Detecting multiple adulterants in dry milk using Raman chemical imaging

    NASA Astrophysics Data System (ADS)

    Qin, Jianwei; Chao, Kuanglin; Kim, Moon S.

    2012-05-01

    This study investigated the potential of Raman chemical imaging for simultaneously detecting multiple adulterants in milk powder. Potential chemical adulterants, including ammonium sulfate, dicyandiamide, melamine, and urea, were together mixed into nonfat dry milk in the concentration range of 0.1%-5.0% for each adulterant. A benchtop point-scan Raman imaging system using a 785-nm laser was assembled to acquire hyperspectral images in the wavenumber range of 102-2538 cm-1. Each mixture was imaged in an area of 25×25 mm2 with a spatial resolution of 0.25 mm. Selfmodeling mixture analysis (SMA) was used to extract pure component spectra, by which the four types of the adulterants were identified at all concentration levels based on their spectral information divergence values to the reference spectra. Raman chemical images were created using the contribution images from SMA, and their use to effectively visualize identification and spatial distribution of the multiple adulterant particles in the dry milk was demonstrated.

  15. A Multiple-Channel Sub-Band Transient Detection System

    SciTech Connect

    David A. Smith

    1998-11-01

    We have developed a unique multiple-channel sub-band transient detection system to record transient electromagnetic signals in carrier-dominated radio environments; the system has been used to make unique observations of weak, transient HF signals. The detection system has made these observations possible through improved sensitivity compared to conventional broadband transient detection systems; the sensitivity improvement is estimated to be at least 20 dB. The increase in sensitivity has been achieved through subdivision of the band of interest (an 18 MHz tunable bandwidth) into eight sub-band independent detection channels, each with a 400 kHz bandwidth and its own criteria. The system generates a system trigger signal when a predetermined number of channels (typically five) trigger within a predetermined window of time (typically 100 ~s). Events are recorded with a broadband data acquisition system sampling at 50 or 100 Msample/s, so despite the fact that the detection system operates on portions of the signal confined to narrow bands, data acquisition is broadband. Between May and September of 1994, the system was used to detect and record over six thousand transient events in the frequency band from 3 to 30 MHz. Approximately 500 of the events have been characterized as paired bursts of radio noise with individual durations of 2 to 10 ps and separations between the bursts of 5 to 160 ps. The paired transients are typically 5 to 40 dB brighter than the background electromagnetic spectrum between carrier signals. We have termed these events SubIonospheric Pulse Pairs (SIPPS) and presently have no explanation as to their source. Our observations of SIPPS resemble observations of TransIonospheric Pulse Pairs (TIPPs) recorded by the Blackboard instrument on the ALEXIS satellite; the source of TIPP events is also unknown. Most of the recorded SIPP events do not exhibit frequency dispersion, implying propagation along a line-of-sight (groundwave) path; but seven of

  16. Use of Gold Nanoparticles to Detect Water Uptake in Vascular Plants

    PubMed Central

    Hwang, Bae Geun; Ahn, Sungsook; Lee, Sang Joon

    2014-01-01

    Direct visualization of water-conducting pathways and sap flows in xylem vessels is important for understanding the physiology of vascular plants and their sap ascent. Gold nanoparticles (AuNPs) combined with synchrotron X-ray imaging technique is a new promising tool for investigating plant hydraulics in opaque xylem vessels of vascular plants. However, in practical applications of AuNPs for real-time quantitative visualization of sap flows, their interaction with a vascular network needs to be verified in advance. In this study, the effect of AuNPs on the water-refilling function of xylem vessels is experimentally investigated with three monocot species. Discrepancy in the water uptakes starts to appear at about 20 min to 40 min after the supply of AuNP solution to the test plant by the possible gradual accumulation of AuNPs on the internal structures of vasculature. However conclusively, it is observed that the water-refilling speeds in individual xylem vessels are virtually unaffected by hydrophilically surface-modified AuNPs (diameter ∼20 nm). Therefore, the AuNPs can be effectively used as flow tracers in the xylem vessels in the first 20∼30 min without any physiological barrier. As a result, AuNPs are found to be useful for visualizing various fluid dynamic phenomena occurring in vascular plants. PMID:25502567

  17. Multiple-instance learning for breast cancer detection in mammograms.

    PubMed

    Sánchez de la Rosa, Rubén; Lamard, Mathieu; Cazuguel, Guy; Coatrieux, Gouenou; Cozic, Michel; Quellec, Gwenolé

    2015-08-01

    This paper describes an experimental computer-aided detection and diagnosis system for breast cancer, the most common form of cancer among women, using mammography. The system relies on the Multiple-Instance Learning (MIL) paradigm, which has proven useful for medical decision support in previous works from our team. In the proposed framework, the breasts are first partitioned adaptively into regions. Then, either textural features, or features derived from the detection of masses and microcalcifications, are extracted from each region. Finally, feature vectors extracted from each region are combined using an MIL algorithm (Citation k-NN or mi-Graph), in order to recognize "normal" mammography examinations or to categorize examinations as "normal", "benign" or "cancer". An accuracy of 91.1% (respectively 62.1%) was achieved for normality recognition (respectively three-class categorization) in a subset of 720 mammograms from the DDSM dataset. The paper also discusses future improvements, that will make the most of the MIL paradigm, in order to improve "benign" versus "cancer" discrimination in particular. PMID:26737917

  18. Protein interaction sentence detection using multiple semantic kernels

    PubMed Central

    2011-01-01

    Background Detection of sentences that describe protein-protein interactions (PPIs) in biomedical publications is a challenging and unresolved pattern recognition problem. Many state-of-the-art approaches for this task employ kernel classification methods, in particular support vector machines (SVMs). In this work we propose a novel data integration approach that utilises semantic kernels and a kernel classification method that is a probabilistic analogue to SVMs. Semantic kernels are created from statistical information gathered from large amounts of unlabelled text using lexical semantic models. Several semantic kernels are then fused into an overall composite classification space. In this initial study, we use simple features in order to examine whether the use of combinations of kernels constructed using word-based semantic models can improve PPI sentence detection. Results We show that combinations of semantic kernels lead to statistically significant improvements in recognition rates and receiver operating characteristic (ROC) scores over the plain Gaussian kernel, when applied to a well-known labelled collection of abstracts. The proposed kernel composition method also allows us to automatically infer the most discriminative kernels. Conclusions The results from this paper indicate that using semantic information from unlabelled text, and combinations of such information, can be valuable for classification of short texts such as PPI sentences. This study, however, is only a first step in evaluation of semantic kernels and probabilistic multiple kernel learning in the context of PPI detection. The method described herein is modular, and can be applied with a variety of feature types, kernels, and semantic models, in order to facilitate full extraction of interacting proteins. PMID:21569604

  19. Toxicity of Gamma Knife Radiosurgery in the Treatment of Intracranial Tumors in Patients With Collagen Vascular Diseases or Multiple Sclerosis

    SciTech Connect

    Lowell, Dot; Tatter, Stephen B.; Bourland, J. Daniel; Guzman, Allan F. de; Ekstrand, Kenneth E.; Ellis, Thomas L.; Lovato, James F.; McMullen, Kevin P.; Munley, Michael T.; Shaw, Edward G.; Urbanic, James J.; Chan, Michael D.

    2011-11-15

    Purpose: To assess toxicity in patients with either a collagen vascular disease (CVD) or multiple sclerosis (MS) treated with intracranial radiosurgery. Methods and Materials: Between January 2004 and April 2009, 6 patients with MS and 14 patients with a CVD were treated with Gamma Knife radiosurgery (GKRS) for intracranial tumors. Treated lesions included 15 total brain metastases in 7 patients, 11 benign brain tumors, 1 low grade glioma, and 1 cavernous malformation. Toxicities were graded by the Radiation Therapy Oncology Group Acute/Late Radiation Morbidity Scoring Criteria. 'Rare toxicities' were characterized as those reported in the scientific literature at an incidence of <5%. Results: Median follow-up time was 16 months. Median dose to the tumor margin was 13.0 Gy (range, 12-21 Gy). Median size of tumor was 5.0 cm{sup 3} (range, 0.14-7.8 cm{sup 3}). Of the 14 patients with CVD, none experienced a Grade 3 or 4 toxicity or a toxicity characterized as rare. Of the 6 patients with MS, 3 experienced rare toxicities, and two of these were Grade 3 toxicities. Rare complications included a patient experiencing both communicating hydrocephalus and facial nerve palsy, as well as 2 additional patients with motor cranial nerve palsy. High-grade toxicities included the patient with an acoustic neuroma requiring ventriculoperitoneal shunt placement for obstructive hydrocephalus, and 1 patient with a facial nerve schwannoma who experienced permanent facial nerve palsy. Interval between radiosurgery and high-grade toxicities ranged from 1 week to 4 months. Conclusions: Our series suggests that patients with MS who receive GKRS may be at increased risk of rare and high-grade treatment-related toxicity. Given the time course of toxicity, treatment-related edema or demyelination represent potential mechanisms.

  20. Proposal of Multiple Detection Method in Human Detection System using Terrestrial Digital TV Waves

    NASA Astrophysics Data System (ADS)

    Nishi, Masahiro; Shin, Koichi; Yoshida, Teruaki

    This paper newly proposes Multiple Detection (MD) method in the human detection system using terrestrial digital TV broadcasting waves. In the conventional human detection system using analog TV waves, human motion in a room can be detected by monitoring Received Signal Strength Indicator (RSSI) of the TV waves. The human detection system using TV waves works in the environments where there are no disturbances such as moving car and passing human outside the room. However, the digitalization of the terrestrial TV system deteriorates the detection performance of this system even in such environments. The radio propagation properties of the digital TV system are different from those of the analog one since the digital system is operated in the Single Frequency Network (SFN). In the SFN environment, there are some rooms under the condition that the received TV waves come from several broadcasting stations with same frequency. In such case, our measurement results indicate that the RSSI hardly fluctuates even under condition of human presence and the detection method only using RSSI has a possibility of overlooking the human motion. In the proposed MD method, not only RSSI but also Carrier to Noise Ratio (CNR) and Bit Error Rate (BER) are utilized for human detection. Today most digital TV tuners are capable of monitoring the quality of received signal, such as CNR and BER in addition to RSSI. In this paper, based on the practical measurements by using the digital TV tuners, we evaluate the fluctuation performances of RSSI, CNR and BER affected by human motion in a wooden detached house, and clarify that the MD method can effectively detect human motion even in the SFN environment.

  1. The detection of cheating in multiple choice examinations

    NASA Astrophysics Data System (ADS)

    Richmond, Peter; Roehner, Bertrand M.

    2015-10-01

    Cheating in examinations is acknowledged by an increasing number of organizations to be widespread. We examine two different approaches to assess their effectiveness at detecting anomalous results, suggestive of collusion, using data taken from a number of multiple-choice examinations organized by the UK Radio Communication Foundation. Analysis of student pair overlaps of correct answers is shown to give results consistent with more orthodox statistical correlations for which confidence limits as opposed to the less familiar "Bonferroni method" can be used. A simulation approach is also developed which confirms the interpretation of the empirical approach. Then the variables Xi =(1 -Ui) Yi +Ui Z are a system of symmetric dependent binary variables (0 , 1 ; p) whose correlation matrix is ρij = r. The proof is easy and given in the paper. Let us add two remarks. • We used the expression "symmetric variables" to reflect the fact that all Xi play the same role. The expression "exchangeable variables" is often used with the same meaning. • The correlation matrix has only positive elements. This is of course imposed by the symmetry condition. ρ12 < 0 and ρ23 < 0 would imply ρ13 > 0, thus violating the symmetry requirement. In the following subsections we will be concerned with the question of uniqueness of the set of Xi generated above. Needless to say, it is useful to know whether the proposition gives the answer or only one among many. More precisely, the problem can be stated as follows.

  2. Textureless Macula Swelling Detection with Multiple Retinal Fundus Images

    SciTech Connect

    Giancardo, Luca; Meriaudeau, Fabrice; Karnowski, Thomas Paul; Tobin Jr, Kenneth William; Grisan, Enrico; Favaro, Paolo; Ruggeri, Alfredo; Chaum, Edward

    2010-01-01

    Retinal fundus images acquired with non-mydriatic digital fundus cameras are a versatile tool for the diagnosis of various retinal diseases. Because of the ease of use of newer camera models and their relatively low cost, these cameras can be employed by operators with limited training for telemedicine or Point-of-Care applications. We propose a novel technique that uses uncalibrated multiple-view fundus images to analyse the swelling of the macula. This innovation enables the detection and quantitative measurement of swollen areas by remote ophthalmologists. This capability is not available with a single image and prone to error with stereo fundus cameras. We also present automatic algorithms to measure features from the reconstructed image which are useful in Point-of-Care automated diagnosis of early macular edema, e.g., before the appearance of exudation. The technique presented is divided into three parts: first, a preprocessing technique simultaneously enhances the dark microstructures of the macula and equalises the image; second, all available views are registered using non-morphological sparse features; finally, a dense pyramidal optical flow is calculated for all the images and statistically combined to build a naiveheight- map of the macula. Results are presented on three sets of synthetic images and two sets of real world images. These preliminary tests show the ability to infer a minimum swelling of 300 microns and to correlate the reconstruction with the swollen location.

  3. Modeling species occurrence dynamics with multiple states and imperfect detection

    USGS Publications Warehouse

    MacKenzie, D.I.; Nichols, J.D.; Seamans, M.E.; Gutierrez, R.J.

    2009-01-01

    Recent extensions of occupancy modeling have focused not only on the distribution of species over space, but also on additional state variables (e.g., reproducing or not, with or without disease organisms, relative abundance categories) that provide extra information about occupied sites. These biologist-driven extensions are characterized by ambiguity in both species presence and correct state classification, caused by imperfect detection. We first show the relationships between independently published approaches to the modeling of multistate occupancy. We then extend the pattern-based modeling to the case of sampling over multiple seasons or years in order to estimate state transition probabilities associated with system dynamics. The methodology and its potential for addressing relevant ecological questions are demonstrated using both maximum likelihood (occupancy and successful reproduction dynamics of California Spotted Owl) and Markov chain Monte Carlo estimation approaches (changes in relative abundance of green frogs in Maryland). Just as multistate capture-recapture modeling has revolutionized the study of individual marked animals, we believe that multistate occupancy modeling will dramatically increase our ability to address interesting questions about ecological processes underlying population-level dynamics. ?? 2009 by the Ecological Society of America.

  4. Indium 111-labeled leukocyte scanning for detection of prosthetic vascular graft infection

    SciTech Connect

    Lawrence, P.F.; Dries, D.J.; Alazraki, N.; Albo, D. Jr.

    1985-01-01

    Recent animal and human studies have suggested that positive indium 111-labeled leukocyte scans may help establish the diagnosis of vascular graft infection; however, there is little information available about the predictive value of both positive and negative leukocyte scans in larger groups of patients. In this study 31 indium 111 leukocyte scans were performed prior to definitive treatment in 21 patients with suspected vascular graft infections. Patients with more than one leukocyte scan performed had either anatomically distinct sites of infection or rescanning of a potentially infected site after definitive treatment. Scans were performed according to the method of Baker et al., attaching 500 muCi of indium 111 to leukocytes with imaging 24 hours later. All patients with positive scans underwent surgical exploration of the area of leukocyte accumulation, with documentation of purulence and culture of the graft. Patients with negative scans were treated as if scan results were indeterminate and underwent surgical exploration for usual clinical indications; if no exploration was performed, the patient was followed up closely for at least 1 year. Twelve of 12 positive scans showed purulence or culture evidence of infection with three different organisms; in 15 instances of negative scans, two operations were performed with one infection noted, whereas no patient without surgery has had a graft infection at 10 months follow-up. In addition to localizing graft infections, two scans demonstrated a nonvascular site of infection. Positive scans also helped determine the extent of infection along the graft, allowing better planning of the surgical procedure. These results indicate that indium 111-labeled leukocyte scans help document and localize prosthetic vascular graft infections.

  5. 111 In-labeled leukocytes in the detection of prosthetic vascular graft infections

    SciTech Connect

    Williamson, M.R.; Boyd, C.M.; Read, R.C.; Thompson, B.W.; Barnes, R.W.; Shah, H.R.; Balachandran, S.; Ferris, E.J.

    1986-07-01

    Making a clinical diagnosis of infection in prosthetic vascular grafts is difficult but when undiagnosed, this condition has a high mortality rate. Using Indium-111-labeled white-blood cells, 30 scans were performed in 21 patients suspected of having a prosthetic graft infection. The diagnosis of infected graft was confirmed by surgery in all cases, and lack of infection was established by resolution of symptoms with conservative therapy. Twenty-four hour scans of autologous Indium-111 leukocytes were obtained, and correlative CT studies were done in 11 cases. There were 13 infected grafts at surgery (purulent material present), and scans were positive in all (100% sensitivity); of 17 scans, there were 15 true negatives and two false positives (88% specificity). Using the criteria of gas or fluid around the graft, the sensitivity of CT was only 37% in a small subset of these patients. One-half of the cases in which infection was suspected clinically had no infection and had negative scans. Various types of grafts and graft materials were used, and there was no correlation with presence or absence of infection on the basis of the type of graft. Extragraft infection sites were found in five patients. In conclusion, use of Indium-111 leukocytes has been found to be an accurate and valuable diagnostic method for evaluation of suspected prosthetic vascular graft infection, and to have higher diagnostic accuracy than CT.

  6. MicroCT angiography detects vascular formation and regression in skin wound healing.

    PubMed

    Urao, Norifumi; Okonkwo, Uzoagu A; Fang, Milie M; Zhuang, Zhen W; Koh, Timothy J; DiPietro, Luisa A

    2016-07-01

    Properly regulated angiogenesis and arteriogenesis are essential for effective wound healing. Tissue injury induces robust new vessel formation and subsequent vessel maturation, which involves vessel regression and remodeling. Although formation of functional vasculature is essential for healing, alterations in vascular structure over the time course of skin wound healing are not well understood. Here, using high-resolution ex vivo X-ray micro-computed tomography (microCT), we describe the vascular network during healing of skin excisional wounds with highly detailed three-dimensional (3D) reconstructed images and associated quantitative analysis. We found that relative vessel volume, surface area and branching number are significantly decreased in wounds from day 7 to days 14 and 21. Segmentation and skeletonization analysis of selected branches from high-resolution images as small as 2.5μm voxel size show that branching orders are decreased in the wound vessels during healing. In histological analysis, we found that the contrast agent fills mainly arterioles, but not small capillaries nor large veins. In summary, high-resolution microCT revealed dynamic alterations of vessel structures during wound healing. This technique may be useful as a key tool in the study of the formation and regression of wound vessels. PMID:27009591

  7. Single photon detection with self-quenching multiplication

    NASA Technical Reports Server (NTRS)

    Zheng, Xinyu (Inventor); Cunningham, Thomas J. (Inventor); Pain, Bedabrata (Inventor)

    2011-01-01

    A photoelectronic device and an avalanche self-quenching process for a photoelectronic device are described. The photoelectronic device comprises a nanoscale semiconductor multiplication region and a nanoscale doped semiconductor quenching structure including a depletion region and an undepletion region. The photoelectronic device can act as a single photon detector or a single carrier multiplier. The avalanche self-quenching process allows electrical field reduction in the multiplication region by movement of the multiplication carriers, thus quenching the avalanche.

  8. Effect of Multiple Testing Adjustment in Differential Item Functioning Detection

    ERIC Educational Resources Information Center

    Kim, Jihye; Oshima, T. C.

    2013-01-01

    In a typical differential item functioning (DIF) analysis, a significance test is conducted for each item. As a test consists of multiple items, such multiple testing may increase the possibility of making a Type I error at least once. The goal of this study was to investigate how to control a Type I error rate and power using adjustment…

  9. [Vascular parkinsonism].

    PubMed

    Yamanouchi, H

    1997-01-01

    Critchley speculated that multiple vascular lesions of the basal ganglia must have an etiological connection to the symptoms of so-called vascular parkinsonism (VP), but without neuropathological confirmation. Some had doubts about its existence because of the lack of the pathologically confirmed case with adequate clinical correlation. At present, VP is characterized clinically by the short-stepped or frozen gait, lead-pipe rigidity, the symmetry of findings, absence of resting tremor, and negative response to levodopa in elderly patients with cerebrovascular lesions on CT/MRI. Pseudobulbar palsies, pyramidal tract findings, and/or multi-infarct dementia coexist in some of the cases. Most of clinically suspected VP patients have cerebral white matter lesions as well as basal ganglia lesions. PMID:9014431

  10. Microfabricated capillary electrophoresis chip and method for simultaneously detecting multiple redox labels

    DOEpatents

    Mathies, Richard A.; Singhal, Pankaj; Xie, Jin; Glazer, Alexander N.

    2002-01-01

    This invention relates to a microfabricated capillary electrophoresis chip for detecting multiple redox-active labels simultaneously using a matrix coding scheme and to a method of selectively labeling analytes for simultaneous electrochemical detection of multiple label-analyte conjugates after electrophoretic or chromatographic separation.

  11. Multiple pedestrian detection using IR LED stereo camera

    NASA Astrophysics Data System (ADS)

    Ling, Bo; Zeifman, Michael I.; Gibson, David R. P.

    2007-09-01

    As part of the U.S. Department of Transportations Intelligent Vehicle Initiative (IVI) program, the Federal Highway Administration (FHWA) is conducting R&D in vehicle safety and driver information systems. There is an increasing number of applications where pedestrian monitoring is of high importance. Visionbased pedestrian detection in outdoor scenes is still an open challenge. People dress in very different colors that sometimes blend with the background, wear hats or carry bags, and stand, walk and change directions unpredictably. The background is various, containing buildings, moving or parked cars, bicycles, street signs, signals, etc. Furthermore, existing pedestrian detection systems perform only during daytime, making it impossible to detect pedestrians at night. Under FHWA funding, we are developing a multi-pedestrian detection system using IR LED stereo camera. This system, without using any templates, detects the pedestrians through statistical pattern recognition utilizing 3D features extracted from the disparity map. A new IR LED stereo camera is being developed, which can help detect pedestrians during daytime and night time. Using the image differencing and denoising, we have also developed new methods to estimate the disparity map of pedestrians in near real time. Our system will have a hardware interface with the traffic controller through wireless communication. Once pedestrians are detected, traffic signals at the street intersections will change phases to alert the drivers of approaching vehicles. The initial test results using images collected at a street intersection show that our system can detect pedestrians in near real time.

  12. Multiple headspace extraction for gas detection in ionic liquids.

    PubMed

    Müller, D; Fühl, M; Pinkwart, K; Baltes, N

    2014-10-16

    In this study multiple headspace extraction was used for the first time to measure the saturation concentration of carbon monoxide and oxygen in various ionic liquids (ILs). Many processes in ILs involve the reaction of gases so that the reactant solubility is not a mere characteristical parameter, but understanding the solubility of gases in ILs is required for assessing the feasibility of possible applications. Multiple headspace extraction has proofed to be a powerful tool to obtain solubilities in good accordance with literature data. The measured saturation concentration for carbon monoxide and oxygen in ILs based on rarely researched tetracyanoborates and other anions was in the range of 1.5-6.5mmol/L. The great advantage of multiple headspace extraction is that it is a nonexpensive method that can be realised in most analytical laboratories by combination of a simple gas chromatograph and an eligible headspace injector. PMID:25458524

  13. Homocysteinemia control by cysteine in cerebral vascular patients after methionine loading test: evidences in physiological and pathological conditions in cerebro-vascular and multiple sclerosis patients.

    PubMed

    Ulivelli, Monica; Priora, Raffaella; Di Giuseppe, Danila; Coppo, Lucia; Summa, Domenico; Margaritis, Antonios; Frosali, Simona; Bartalini, Sabina; Martini, Giuseppe; Cerase, Alfonso; Di Simplicio, Paolo

    2016-06-01

    The toxicity risk of hyperhomocysteinemia is prevented through thiol drug administration which reduces plasma total homocysteine (tHcy) concentrations by activating thiol exchange reactions. Assuming that cysteine (Cys) is a homocysteinemia regulator, the hypothesis was verified in healthy and pathological individuals after the methionine loading test (MLT). The plasma variations of redox species of Cys, Hcy, cysteinylglycine, glutathione and albumin (reduced, HS-ALB, and at mixed disulfide, XSS-ALB) were compared in patients with cerebral small vessels disease (CSVD) (n = 11), multiple sclerosis (MS) (n = 12) and healthy controls (n = 11) at 2-4-6 h after MLT. In MLT-treated subjects, the activation of thiol exchange reactions provoked significant changes over time in redox species concentrations of Cys, Hcy, and albumin. Significant differences between controls and pathological groups were also observed. In non-methionine-treated subjects, total Cys concentrations, tHcy and thiol-protein mixed disulfides (CSS-ALB, HSS-ALB) of CSVD patients were higher than controls. After MLT, all groups displayed significant cystine (CSSC) increases and CSS-ALB decreases, that in pathological groups were significantly higher than controls. These data would confirm the Cys regulatory role on the homocysteinemia; they also explain that the Cys-Hcy mixed disulfide excretion is an important point of hyperhomocysteinemia control. Moreover, in all groups after MLT, significant increases in albumin concentrations, named total albumin (tALB) and measured as sum of HS-ALB (spectrophometric), and XSS-ALB (assayed at HPLC) were observed. tALB increases, more pronounced in healthy than in the pathological subjects, could indicate alterations of albumin equilibria between plasma and other extracellular spaces, whose toxicological consequences deserve further studies. PMID:26969256

  14. Vascular Lesions.

    PubMed

    Jahnke, Marla N

    2016-08-01

    Vascular lesions in childhood are comprised of vascular tumors and vascular malformations. Vascular tumors encompass neoplasms of the vascular system, of which infantile hemangiomas (IHs) are the most common. Vascular malformations, on the other hand, consist of lesions due to anomalous development of the vascular system, including the capillary, venous, arterial, and lymphatic systems. Capillary malformations represent the most frequent type of vascular malformation. IHs and vascular malformations tend to follow relatively predictable growth patterns in that IHs grow then involute during early childhood, whereas vascular malformations tend to exhibit little change. Both vascular tumors and vascular malformations can demonstrate a wide range of severity and potential associated complications necessitating specialist intervention when appropriate. Evaluation and treatment of the most common types of vascular lesions are discussed in this article. [Pediatr Ann. 2016;45(8):e299-e305.]. PMID:27517358

  15. Novel application of a multiscale entropy index as a sensitive tool for detecting subtle vascular abnormalities in the aged and diabetic.

    PubMed

    Wu, Hsien-Tsai; Lo, Men-Tzung; Chen, Guan-Hong; Sun, Cheuk-Kwan; Chen, Jian-Jung

    2013-01-01

    Although previous studies have shown the successful use of pressure-induced reactive hyperemia as a tool for the assessment of endothelial function, its sensitivity remains questionable. This study aims to investigate the feasibility and sensitivity of a novel multiscale entropy index (MEI) in detecting subtle vascular abnormalities in healthy and diabetic subjects. Basic anthropometric and hemodynamic parameters, serum lipid profiles, and glycosylated hemoglobin levels were recorded. Arterial pulse wave signals were acquired from the wrist with an air pressure sensing system (APSS), followed by MEI and dilatation index (DI) analyses. MEI succeeded in detecting significant differences among the four groups of subjects: healthy young individuals, healthy middle-aged or elderly individuals, well-controlled diabetic individuals, and poorly controlled diabetic individuals. A reduction in multiscale entropy reflected age- and diabetes-related vascular changes and may serve as a more sensitive indicator of subtle vascular abnormalities compared with DI in the setting of diabetes. PMID:23509600

  16. Novel Application of a Multiscale Entropy Index as a Sensitive Tool for Detecting Subtle Vascular Abnormalities in the Aged and Diabetic

    PubMed Central

    Wu, Hsien-Tsai; Lo, Men-Tzung; Chen, Guan-Hong; Sun, Cheuk-Kwan; Chen, Jian-Jung

    2013-01-01

    Although previous studies have shown the successful use of pressure-induced reactive hyperemia as a tool for the assessment of endothelial function, its sensitivity remains questionable. This study aims to investigate the feasibility and sensitivity of a novel multiscale entropy index (MEI) in detecting subtle vascular abnormalities in healthy and diabetic subjects. Basic anthropometric and hemodynamic parameters, serum lipid profiles, and glycosylated hemoglobin levels were recorded. Arterial pulse wave signals were acquired from the wrist with an air pressure sensing system (APSS), followed by MEI and dilatation index (DI) analyses. MEI succeeded in detecting significant differences among the four groups of subjects: healthy young individuals, healthy middle-aged or elderly individuals, well-controlled diabetic individuals, and poorly controlled diabetic individuals. A reduction in multiscale entropy reflected age- and diabetes-related vascular changes and may serve as a more sensitive indicator of subtle vascular abnormalities compared with DI in the setting of diabetes. PMID:23509600

  17. Multiple-Diode-Laser Gas-Detection Spectrometer

    NASA Technical Reports Server (NTRS)

    Webster, Christopher R.; Beer, Reinhard; Sander, Stanley P.

    1988-01-01

    Small concentrations of selected gases measured automatically. Proposed multiple-laser-diode spectrometer part of system for measuring automatically concentrations of selected gases at part-per-billion level. Array of laser/photodetector pairs measure infrared absorption spectrum of atmosphere along probing laser beams. Adaptable to terrestrial uses as monitoring pollution or control of industrial processes.

  18. Detection of Multiple Waterborne Pathogens Using Microsequencing Arrays

    EPA Science Inventory

    Aims: A microarray was developed to simultaneously detect Cryptosporidium parvum, Cryptosporidium hominis, Enterococcus faecium, Bacillus anthracis and Francisella tularensis in water. Methods and Results: A DNA microarray was designed to contain probes that specifically dete...

  19. Suppression of multiple scattering with a CCD camera detection scheme

    NASA Astrophysics Data System (ADS)

    Zakharov, Pavel; Schurtenberger, Peter; Scheffold, Frank

    2005-06-01

    We introduce a CCD camera detection scheme in dynamic light scattering that provides information on the single-scattered auto-correlation function even for fairly turbid samples. Our approach allows access to the extensive range of systems that show low-order scattering by selective detection of the singly scattered light. Model experiments on slowly relaxing suspensions of latex spheres in glycerol were carried out to verify validity range of our approach.

  20. Methods and apparatus using commutative error detection values for fault isolation in multiple node computers

    DOEpatents

    Almasi, Gheorghe [Ardsley, NY; Blumrich, Matthias Augustin [Ridgefield, CT; Chen, Dong [Croton-On-Hudson, NY; Coteus, Paul [Yorktown, NY; Gara, Alan [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Hoenicke, Dirk I [Ossining, NY; Singh, Sarabjeet [Mississauga, CA; Steinmacher-Burow, Burkhard D [Wernau, DE; Takken, Todd [Brewster, NY; Vranas, Pavlos [Bedford Hills, NY

    2008-06-03

    Methods and apparatus perform fault isolation in multiple node computing systems using commutative error detection values for--example, checksums--to identify and to isolate faulty nodes. When information associated with a reproducible portion of a computer program is injected into a network by a node, a commutative error detection value is calculated. At intervals, node fault detection apparatus associated with the multiple node computer system retrieve commutative error detection values associated with the node and stores them in memory. When the computer program is executed again by the multiple node computer system, new commutative error detection values are created and stored in memory. The node fault detection apparatus identifies faulty nodes by comparing commutative error detection values associated with reproducible portions of the application program generated by a particular node from different runs of the application program. Differences in values indicate a possible faulty node.

  1. Prognostic significance of computed tomography-detected extramural vascular invasion in colon cancer

    PubMed Central

    Yao, Xun; Yang, Su-Xing; Song, Xing-He; Cui, Yan-Cheng; Ye, Ying-Jiang; Wang, Yi

    2016-01-01

    AIM To compare disease-free survival (DFS) between extramural vascular invasion (EMVI)-positive and -negative colon cancer patients evaluated by computed tomography (CT). METHODS Colon cancer patients (n = 194) undergoing curative surgery between January 2009 and December 2013 were included. Each patient’s demographics, cancer characteristics, EMVI status, pathological status and survival outcomes were recorded. All included patients had been routinely monitored until December 2015. EMVI was defined as tumor tissue within adjacent vessels beyond the colon wall as seen on enhanced CT. Disease recurrence was defined as metachronous metastases, local recurrence, or death due to colon cancer. Kaplan-Meier analyses were used to compare DFS between the EMVI-positive and -negative groups. Cox’s proportional hazards models were used to measure the impact of confounding variables on survival rates. RESULTS EMVI was observed on CT (ctEMVI) in 60 patients (30.9%, 60/194). One year after surgery, there was no statistically significant difference regarding the rates of progressive events between EMVI-positive and -negative patients [11.7% (7/60) and 6.7% (9/134), respectively; P = 0.266]. At the study endpoint, the EMVI-positive patients had significantly more progressive events than the EMVI-negative patients [43.3% (26/60) and 14.9% (20/134), respectively; odds ratio = 4.4, P < 0.001]. Based on the Kaplan-Meier method, the cumulative 1-year DFS rates were 86.7% (95%CI: 82.3-91.1) and 92.4% (95%CI: 90.1-94.7) for EMVI-positive and EMVI-negative patients, respectively. The cumulative 3-year DFS rates were 49.5% (95%CI: 42.1-56.9) and 85.8% (95%CI: 82.6-89.0), respectively. Cox proportional hazards regression analysis revealed that ctEMVI was an independent predictor of DFS with a hazard ratio of 2.15 (95%CI: 1.12-4.14, P = 0.023). CONCLUSION ctEMVI may be helpful when evaluating disease progression in colon cancer patients.

  2. Using Korotkoff Sounds to Detect the Degree of Vascular Compliance in Different Age Groups

    PubMed Central

    2016-01-01

    Introduction The principle behind the generation of the Korotkoff sounds is the turbulence of blood flowing through a partially occluded area in the artery. With increasing age, the vascular wall compliance is expected to decrease, which is due to the thickening of the vessel wall, due to which the amplitude of the transmitted Korotkoff sounds is decreased. There is also an accompanying rise in the systolic B.P. and pulse pressure. Aim To record and compare the amplitudes of the intermediate Korotkoff sounds and the blood pressures in individuals of the two age groups, and calculate the pulse pressure and determine whether they vary in relation to the amplitude of the intermediate Korotkoff sounds recorded. Materials and Methods The cross-sectional study was conducted on 50 young subjects (15-25 years) and 50 older subjects (50-70 years). The mid arm circumference was measured using a tape. A phonoarteriogram was placed over the left brachial artery and the sphygmomanometer cuff was tied 2cm above the cubital fossa of the left arm. The blood pressure was recorded using the Lab Tutor software. The Korotkoff sounds picked up and transmitted by the phonoarteriogram are represented as distinct lines on the graphical recording. Statistical Analysis Independent samples t-test to look for significant mean amplitude differences and for correlating mean amplitude and pulse pressure. Null hypothesis rejected at p<0.05. Data analysed using the SPSS software version 20.0 (SPSS Inc.). Results There was a significant difference in the mean amplitudes of Korotkoff sounds among the different age groups (p=0.001) and subject categories (p=0.043 among males, p=0.037 among females). A significant difference in pulse pressures was also seen among different age groups and subject categories. The decrease in the amplitudes of Korotkoff sounds in the older age group accompanies the increase in pulse pressures seen in this group and the same was seen among the different age groups within

  3. Detection of nucleic acids by multiple sequential invasive cleavages

    DOEpatents

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann D.

    1999-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of human cytomegalovirus nucleic acid in a sample.

  4. Detection of nucleic acids by multiple sequential invasive cleavages 02

    DOEpatents

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann D.

    2002-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of human cytomegalovirus nucleic acid in a sample.

  5. Detection of nucleic acids by multiple sequential invasive cleavages

    DOEpatents

    Hall, Jeff G; Lyamichev, Victor I; Mast, Andrea L; Brow, Mary Ann D

    2012-10-16

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of human cytomegalovirus nucleic acid in a sample.

  6. Multiple-modality program for standoff detection of roadside hazards

    NASA Astrophysics Data System (ADS)

    Williams, Kathryn; Middleton, Seth; Close, Ryan; Luke, Robert H.; Suri, Rajiv

    2016-05-01

    The U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) is executing a program to assess the performance of a variety of sensor modalities for standoff detection of roadside explosive hazards. The program objective is to identify an optimal sensor or combination of fused sensors to incorporate with autonomous detection algorithms into a system of systems for use in future route clearance operations. This paper provides an overview of the program, including a description of the sensors under consideration, sensor test events, and ongoing data analysis.

  7. Iris Image Blur Detection with Multiple Kernel Learning

    NASA Astrophysics Data System (ADS)

    Pan, Lili; Xie, Mei; Mao, Ling

    In this letter, we analyze the influence of motion and out-of-focus blur on both frequency spectrum and cepstrum of an iris image. Based on their characteristics, we define two new discriminative blur features represented by Energy Spectral Density Distribution (ESDD) and Singular Cepstrum Histogram (SCH). To merge the two features for blur detection, a merging kernel which is a linear combination of two kernels is proposed when employing Support Vector Machine. Extensive experiments demonstrate the validity of our method by showing the improved blur detection performance on both synthetic and real datasets.

  8. Multiple Pathogen Detection Using Biosensors: Advancements and Challenges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Advancements in biosensor research have considerably impacted clinical diagnostics for human health. Efforts in capitalizing on the sensitivity of biosensors for food pathogen detection are evident in the food safety/security research community. For practical application with foods that normally h...

  9. Assessing bat detectability and occupancy with multiple automated echolocation detectors

    USGS Publications Warehouse

    Gorresen, P.M.; Miles, A.C.; Todd, C.M.; Bonaccorso, F.J.; Weller, T.J.

    2008-01-01

    Occupancy analysis and its ability to account for differential detection probabilities is important for studies in which detecting echolocation calls is used as a measure of bat occurrence and activity. We examined the feasibility of remotely acquiring bat encounter histories to estimate detection probability and occupancy. We used echolocation detectors coupled to digital recorders operating at a series of proximate sites on consecutive nights in 2 trial surveys for the Hawaiian hoary bat (Lasiurus cinereus semotus). Our results confirmed that the technique is readily amenable for use in occupancy analysis. We also conducted a simulation exercise to assess the effects of sampling effort on parameter estimation. The results indicated that the precision and bias of parameter estimation were often more influenced by the number of sites sampled than number of visits. Acceptable accuracy often was not attained until at least 15 sites or 15 visits were used to estimate detection probability and occupancy. The method has significant potential for use in monitoring trends in bat activity and in comparative studies of habitat use. ?? 2008 American Society of Mammalogists.

  10. Radiation detector having a multiplicity of individual detecting elements

    DOEpatents

    Whetten, Nathan R.; Kelley, John E.

    1985-01-01

    A radiation detector has a plurality of detector collection element arrays immersed in a radiation-to-electron conversion medium. Each array contains a multiplicity of coplanar detector elements radially disposed with respect to one of a plurality of positions which at least one radiation source can assume. Each detector collector array is utilized only when a source is operative at the associated source position, negating the necessity for a multi-element detector to be moved with respect to an object to be examined. A novel housing provides the required containment of a high-pressure gas conversion medium.

  11. A protocol for phenotypic detection and characterization of vascular cells of different origins in a lung neovascularization model in rodents

    PubMed Central

    Jones, Rosemary C; Capen, Diane E; Cohen, Kenneth S; Munn, Lance L; Jain, Rakesh K; Duda, Dan G

    2009-01-01

    The goal of many current studies of neovascularization is to define the phenotype of vascular cell populations of different origins and to determine how such cells promote assembly of vascular channel. Here, we describe a protocol to immunophenotype vascular cells by high-resolution imaging and by fluorescence-activated flow cytometry in an in vivo rodent model of pulmonary microvascular remodeling. Analysis of cells by this combined approach will characterize their phenotype, quantify their number and identify their role in the assembly of vascular channels. PMID:18323810

  12. Multiple phases in modularity-based community detection

    NASA Astrophysics Data System (ADS)

    Schülke, Christophe; Ricci-Tersenghi, Federico

    2015-10-01

    Detecting communities in a network, based only on the adjacency matrix, is a problem of interest to several scientific disciplines. Recently, Zhang and Moore have introduced an algorithm [Proc. Natl. Acad. Sci. USA 111, 18144 (2014), 10.1073/pnas.1409770111], called mod-bp, that avoids overfitting the data by optimizing a weighted average of modularity (a popular goodness-of-fit measure in community detection) and entropy (i.e., number of configurations with a given modularity). The adjustment of the relative weight, the "temperature" of the model, is crucial for getting a correct result from mod-bp. In this work we study the many phase transitions that mod-bp may undergo by changing the two parameters of the algorithm: the temperature T and the maximum number of groups q . We introduce a new set of order parameters that allow us to determine the actual number of groups q ̂, and we observe on both synthetic and real networks the existence of phases with any q ̂∈{1 ,q } , which were unknown before. We discuss how to interpret the results of mod-bp and how to make the optimal choice for the problem of detecting significant communities.

  13. Concealed Threat Detection at Multiple Frames-per-second

    SciTech Connect

    Chang, J T

    2005-11-08

    In this LDRD project, our research purpose is to investigate the science and technology necessary to enable real-time array imaging as a rapid way to detect hidden threats through obscurants such as smoke, fog, walls, doors, and clothing. The goal of this research is to augment the capabilities of protective forces in concealed threat detection. In the current context, threats include people as well as weapons. In most cases, security personnel must make very fast assessments of a threat based upon limited amount of data. Among other attributes, UWB has been shown and quantified to penetrate and propagate through many materials (wood, some concretes, non-metallic building materials, some soils, etc.) while maintaining high range resolution. We have build collaborations with university partners and government agencies. We have considered the impact of psychometrics on target recognition and identification. Specifically we have formulated images in real-time that will engage the user's vision system in a more active way to enhance image interpretation capabilities. In this project, we are researching the use of real time (field programmable gate arrays) integrated with high resolution (cm scale), ultra wide band (UWB) electromagnetic signals for imaging personnel through smoke and walls. We evaluated the ability of real-time UWB imaging for detecting smaller objects, such as concealed weapons that are carried by the obscured personnel. We also examined the cognitive interpretation process of real time UWB electromagnetic images.

  14. Development of an oligonucleotide-based microarray to detect multiple foodborne pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli O157:H7, Salmonella enterica, Listeria monocytogenes and Campylobacter jejuni are considered important human pathogens causing the most food-related human illnesses worldwide. Current methods for pathogen detection have limitations in effectively identifying multiple foodborne patho...

  15. Development of an oligonucleotide-based microarray to detect multiple foodborne pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and Campylobacter jejuni are considered important foodborne bacterial pathogens causing the most food-related human illnesses worldwide. Current methods for pathogen detection have limitations in effectively identifying multiple foodb...

  16. Detection and location of multiple events by MARS. Final report. [Multiple Arrival Recognition System

    SciTech Connect

    Wang, J.; Masso, J.F.; Archambeau, C.B.; Savino, J.M.

    1980-09-01

    Seismic data from two explosions was processed using the Systems Science and Software MARS (Multiple Arrival Recognition System) seismic event detector in an effort to determine their relative spatial and temporal separation on the basis of seismic data alone. The explosions were less than 1.0 kilometer apart and were separated by less than 0.5 sec in origin times. The seismic data consisted of nine local accelerograms (r < 1.0 km) and four regional (240 through 400 km) seismograms. The MARS processing clearly indicates the presence of multiple explosions, but the restricted frequency range of the data inhibits accurate time picks and hence limits the precision of the event location.

  17. Vascular Function in Alzheimer's Disease and Vascular Dementia.

    PubMed

    Tachibana, Hisatsugu; Washida, Kazuo; Kowa, Hisatomo; Kanda, Fumio; Toda, Tatsushi

    2016-08-01

    We investigated vascular functioning in patients with a clinical and radiological diagnosis of either Alzheimer's disease (AD) or vascular dementia (VaD) and examined a possible relationship between vascular function and cognitive status. Twenty-seven patients with AD, 23 patients with VaD, and 26 healthy control patients underwent measurements of flow-mediated dilation (FMD), ankle-brachial index (ABI), cardioankle vascular index (CAVI), and intima-media thickness (IMT). The FMD was significantly lower in patients with AD or VaD compared to controls. There were no significant differences in ABI, CAVI, or IMT among the 3 groups. A significant correlation was found between Mini-Mental State Examination (MMSE) scores and FMD. Furthermore, a multiple regression analysis revealed that FMD was significantly predicted by MMSE scores. These results suggest that endothelial involvement plays a role in AD pathogenesis, and FMD may be more sensitive than other surrogate methods (ABI, CAVI, and IMT) for detecting early-stage atherosclerosis and/or cognitive decline. PMID:27284205

  18. Direct Carotid Cavernous Fistula of an Adult-Type Persistent Primitive Trigeminal Artery with Multiple Vascular Variations

    PubMed Central

    Jin, Sung-Chul; Park, Hyun; Choi, Choong-Gon

    2011-01-01

    We report a case of spontaneous right carotid-cavernous fistula (CCF) in a proximal segment of persistent primitive trigeminal artery (PPTA) and combined vascular anomalies such as left duplicated hypoplastic proximal posterior cerebral arteries and a variation of anterior choroidal artery supplying temporal and occipital lobe. A 45-year-old male presented with progressive right exophthalmos, diplopia, and ocular pain. With manual compression of the internal carotid artery, a cerebral angiography revealed a right CCF from a PPTA. Treatment involved the placement of detachable non-fibered and fibered coils, and use of a hyperglide balloon to protect against coil herniation into the internal carotid artery. A final angiograph revealed complete occlusion of PPTA resulted in no contrast filling of CCF. PMID:21607181

  19. Direct carotid cavernous fistula of an adult-type persistent primitive trigeminal artery with multiple vascular variations.

    PubMed

    Jin, Sung-Chul; Park, Hyun; Kwon, Do Hoon; Choi, Choong-Gon

    2011-04-01

    We report a case of spontaneous right carotid-cavernous fistula (CCF) in a proximal segment of persistent primitive trigeminal artery (PPTA) and combined vascular anomalies such as left duplicated hypoplastic proximal posterior cerebral arteries and a variation of anterior choroidal artery supplying temporal and occipital lobe. A 45-year-old male presented with progressive right exophthalmos, diplopia, and ocular pain. With manual compression of the internal carotid artery, a cerebral angiography revealed a right CCF from a PPTA. Treatment involved the placement of detachable non-fibered and fibered coils, and use of a hyperglide balloon to protect against coil herniation into the internal carotid artery. A final angiograph revealed complete occlusion of PPTA resulted in no contrast filling of CCF. PMID:21607181

  20. Effects of Multiple Listenings on Error-Detection Acuity in Multivoice, Multitimbral Musical Examples

    ERIC Educational Resources Information Center

    Sheldon, Deborah A.

    2004-01-01

    This study is an investigation of the effects of multiple listenings on error-detection identification and labeling accuracy among brass and woodwind instrumentalists. Examples derived from band music used balanced four-voice incipits performed with differing timbres, and errors that occurred in one or multiple voices. Response rates for correct…

  1. Optimal edge detection using multiple operators for image understanding

    NASA Astrophysics Data System (ADS)

    Giannarou, Stamatia; Stathaki, Tania

    2011-12-01

    Extraction of features, such as edges for the understanding of aerial images, has been an important objective since the early days of remote sensing. This work aims at describing a new framework which allows for the quantitative combination of a preselected set of edge detectors based on the correspondence between their outcomes. This is inspired from the problem that despite the enormous amount of literature on edge detection techniques, there is no single technique that performs well in every possible image context. Two approaches are proposed for this purpose. The first approach is the well-known receiver operating characteristics analysis which is introduced for a sound quality evaluation of the edge maps estimated by combining different edge detectors. In the second approach, the so-called kappa statistics are employed in a novel fashion to amalgamate the above-mentioned selected edge maps to form an improved final edge image. This method is unique in the sense that the balance between the false detections (false positives and false negatives) is explicitly determined in advance and incorporated in the proposed method in a mathematical fashion. For the performance evaluation of the proposed techniques, a sample set of the RADIUS/DARPA-IU Fort Hood aerial image database with known ground truth has been used.

  2. Automatic Detection of Multiple Sclerosis Lesions in MR Brain Images

    PubMed Central

    Kapouleas, Ioannis

    1989-01-01

    This paper describes a system that locates lesions in Magnetic Resonance (MR) human brain images. The system uses new low level vision methods which successively identify the brain mass in the images, locate suspected lesions, sulci, and other normal structures. Other low level methods eliminate the majority of false positive lesions and locate certain landmarks such as the interhemispherical fissure. These methods take advantage of the special characteristics of MR images. A modeling method that employs b-spline surfaces has been developed to model the surfaces of the organs in a human brain in 3D. This method allows the model surfaces to be deformed in order to fit each individual patient's brain, and also allows the proportional deformation of the shapes of difficult-to-identify organs according to the deformation of easier-to-identify organs. The system calculates the appropriate position and orientation for the model by making use of landmarks within the patient's brain, and the moment of inertia method. The system uses both Proton Density and T2 sequences of images, in coronal and axial orientations. The various parts of the system have been tested extensively (on more than 1000 images from patients with Multiple Sclerosis lesions) with very good results. The methods developed here can also be used for other diagnostic tasks in radiology. ImagesFigures 1to7 10 11

  3. Anomaly Detection in Multiple Scale for Insider Threat Analysis

    SciTech Connect

    Kim, Yoohwan; Sheldon, Frederick T; Hively, Lee M

    2012-01-01

    We propose a method to quantify malicious insider activity with statistical and graph-based analysis aided with semantic scoring rules. Different types of personal activities or interactions are monitored to form a set of directed weighted graphs. The semantic scoring rules assign higher scores for the events more significant and suspicious. Then we build personal activity profiles in the form of score tables. Profiles are created in multiple scales where the low level profiles are aggregated toward more stable higherlevel profiles within the subject or object hierarchy. Further, the profiles are created in different time scales such as day, week, or month. During operation, the insider s current activity profile is compared to the historical profiles to produce an anomaly score. For each subject with a high anomaly score, a subgraph of connected subjects is extracted to look for any related score movement. Finally the subjects are ranked by their anomaly scores to help the analysts focus on high-scored subjects. The threat-ranking component supports the interaction between the User Dashboard and the Insider Threat Knowledge Base portal. The portal includes a repository for historical results, i.e., adjudicated cases containing all of the information first presented to the user and including any additional insights to help the analysts. In this paper we show the framework of the proposed system and the operational algorithms.

  4. UTILIZATION OF PHOSWICH DETECTORS FOR SIMULTANEOUS, MULTIPLE RADIATION DETECTION

    SciTech Connect

    William H. Miller; Manuel Diaz de Leon

    2003-04-15

    A phoswich radiation detector is comprised of a phosphor sandwich in which several different phosphors are viewed by a common photomultiplier. By selecting the appropriate phosphors, this system can be used to simultaneously measure multiple radiation types (alpha, beta, gamma and/or neutron) with a single detector. Differentiation between the signals from the different phosphors is accomplished using digital pulse shape discrimination techniques. This method has been shown to result in accurate discrimination with highly reliable and versatile digital systems. This system also requires minimal component count (i.e. only the detector and a computer for signal processing). A variety of detectors of this type have been built and tested including: (1) a triple phoswich system for alpha/beta/gamma swipe counting, (2) two well-type detectors for measuring low levels of low energy photons in the presence of a high energy background, (3) a large area detector for measuring beta contamination in the presence of a photon background, (4) another large area detector for measuring low energy photons from radioactive elements such as uranium in the presence of a photon background. An annular geometry, triple phoswich system optimized for measuring alpha/beta/gamma radiation in liquid waste processing streams is currently being designed.

  5. Multiple Marker Detection in Peripheral Blood for NSCLC Diagnosis

    PubMed Central

    Ulivi, Paola; Mercatali, Laura; Casoni, Gian-Luca; Scarpi, Emanuela; Bucchi, Lauro; Silvestrini, Rosella; Sanna, Stefano; Monteverde, Marco; Amadori, Dino; Poletti, Venerino; Zoli, Wainer

    2013-01-01

    Background Non-invasive early detection of lung cancer could reduce the number of patients diagnosed with advanced disease, which is associated with a poor prognosis. We analyzed the diagnostic accuracy of a panel of peripheral blood markers in detecting non small cell lung cancer (NSCLC). Methods 100 healthy donors and 100 patients with NSCLC were enrolled onto this study. Free circulating DNA, circulating mRNA expression of peptidylarginine deiminase type 4 (PAD4/PADI4), pro-platelet basic protein (PPBP) and haptoglobin were evaluated using a Real-Time PCR-based method. Results Free circulating DNA, PADI4, PPBP and haptoglobin levels were significantly higher in NSCLC patients than in healthy donors (p<0.0001, p<0.0001, p = 0.0002 and p = 0.0001, respectively). The fitted logistic regression model demonstrated a significant direct association between marker expression and lung cancer risk. The odds ratios of individual markers were 6.93 (95% CI 4.15–11.58; p<0.0001) for free DNA, 6.99 (95% CI 3.75–13.03; p<0.0001) for PADI4, 2.85 (95% CI 1.71–4.75; p<0.0001) for PPBP and 1.16 (95% CI 1.01–1.33; p = 0.031) for haptoglobin. Free DNA in combination with PPBP and PADI4 gave an area under the ROC curve of 0.93, 95% CI = 0.90–0.97, with sensitivity and specificity over 90%. Conclusions Free circulating DNA analysis combined with PPBP and PADI4 expression determination appears to accurately discriminate between healthy donors and NSCLC patients. This non-invasive multimarker approach warrants further research to assess its potential role in the diagnostic or screening workup of subjects with suspected lung cancer. PMID:23468981

  6. Detection of multiple airborne targets from multisensor data

    NASA Astrophysics Data System (ADS)

    Foltz, Mark A.; Srivastava, Anuj; Miller, Michael I.; Grenander, Ulf

    1995-08-01

    Previously we presented a jump-diffusion based random sampling algorithm for generating conditional mean estimates of scene representations for the tracking and recongition of maneuvering airborne targets. These representations include target positions and orientations along their trajectories and the target type associated with each trajectory. Taking a Bayesian approach, a posterior measure is defined on the parameter space by combining sensor models with a sophisticated prior based on nonlinear airplane dynamics. The jump-diffusion algorithm constructs a Markov process which visits the elements of the parameter space with frequencies proportional to the posterior probability. It consititutes both the infinitesimal, local search via a sample path continuous diffusion transform and the larger, global steps through discrete jump moves. The jump moves involve the addition and deletion of elements from the scene configuration or changes in the target type assoviated with each target trajectory. One such move results in target detection by the addition of a track seed to the inference set. This provides initial track data for the tracking/recognition algorithm to estimate linear graph structures representing tracks using the other jump moves and the diffusion process, as described in our earlier work. Target detection ideally involves a continuous research over a continuum of the observation space. In this work we conclude that for practical implemenations the search space must be discretized with lattice granularity comparable to sensor resolution, and discuss how fast Fourier transforms are utilized for efficient calcuation of sufficient statistics given our array models. Some results are also presented from our implementation on a networked system including a massively parallel machine architecture and a silicon graphics onyx workstation.

  7. D Quantification of Tumor Vasculature in Lymphoma Xenografts in NOD/SCID Mice Allows to Detect Differences among Vascular-Targeted Therapies

    PubMed Central

    Righi, Marco; Giacomini, Arianna; Cleris, Loredana; Carlo-Stella, Carmelo

    2013-01-01

    Quantitative characterization of the in vivo effects of vascular-targeted therapies on tumor vessels is hampered by the absence of useful 3D vascular network descriptors aside from microvessel density. In this study, we extended the quantification of planar vessel distribution to the analysis of vascular volumes by studying the effects of antiangiogenic (sorafenib and sunitinib) or antivascular (combretastatin A4 phosphate) treatments on the quantity and spatial distributions of thin microvessels. These observations were restricted to perinecrotic areas of treated human multiple myeloma tumors xenografted in immunodeficient mice and to microvessels with an approximate cross-sectional area lower than 75 µm2. Finally, vessel skeletonization minimized artifacts due to possible differential wall staining and allowed a comparison of the various treatment effects. Antiangiogenic drug treatment reduced the number of vessels of every caliber (at least 2-fold fewer vessels vs. controls; p<0.001, n = 8) and caused a heterogeneous distribution of the remaining vessels. In contrast, the effects of combretastatin A4 phosphate mainly appeared to be restricted to a homogeneous reduction in the number of thin microvessels (not more than 2-fold less vs. controls; p<0.001, n = 8) with marginal effects on spatial distribution. Unexpectedly, these results also highlighted a strict relationship between microvessel quantity, distribution and cross-sectional area. Treatment-specific changes in the curves describing this relationship were consistent with the effects ascribed to the different drugs. This finding suggests that our results can highlight differences among vascular-targeted therapies, providing hints on the processes underlying sample vascularization together with the detailed characterization of a pathological vascular tree. PMID:23555747

  8. Long-lasting intestinal bleeding in an old patient with multiple mucosal vascular abnormalities and Glanzmann's thrombasthenia: 3-year pharmacological management.

    PubMed

    Coppola, A; De Stefano, V; Tufano, A; Nardone, G; Amoriello, A; Cerbone, A M; Di Minno, G

    2002-09-01

    A 75-year-old woman with Glanzmann's thrombasthenia was admitted because of persistent melaena. Endoscopic examination showed multiple angiodysplastic lesions, with active bleeding in small and large bowel. Electro-coagulation of some lesions, octreotide, conjugated oestrogens and selective embolization of jejunal vessels did not change transfusion requirements. After 8 month-transfusions, ethinylestradiol + norethisterone in association with octreotide was started, leading to no transfusion over the following 9 months. Bleeding recurred after withdrawing octreotide and substituting ethinylestradiol + norgestrel for the ethinylestradiol + norethisterone combination. Re-introduction of octreotide did not improve bleeding; however, a reduction of transfusion requirement was observed when the ethinylestradiol + norethisterone pill was re-administered. The association of octreotide and of an oestrogen-progesterone combination was helpful in the difficult management of recurrent bleeding in this patient with diffuse gastrointestinal vascular abnormalities and a severe condition predisposing to bleeding. PMID:12270009

  9. Simultaneous detection of randomly arranged multiple barcodes using time division multiplexing technique

    NASA Astrophysics Data System (ADS)

    Haider, Saad Md. Jaglul; Islam, Md. Kafiul

    2010-02-01

    A method of detecting multiple barcodes simultaneously using time division multiplexing technique has been proposed in this paper to minimize the effective time needed for handling multiple tags of barcodes and to lessen the overall workload. Available barcode detection systems can handle multiple types of barcode but a single barcode at a time. This is not so efficient and can create large queue and chaos in places like mega shopping malls or large warehouses where we need to scan huge number of barcodes daily. Our proposed system is expected to improve the real time identification of goods or products on production lines and in automated warehouses or in mega shopping malls in a much more convenient and efficient way. For identifying of multiple barcodes simultaneously, a particular arrangement and orientation of LASER scanner and reflector have been used with a special curve shaped basement where the barcodes are placed. An effective and novel algorithm is developed to extract information from multiple barcodes which introduces starting pattern and ending pattern in barcodes with bit stuffing technique for the convenience of multiple detections. CRC technique is also used for trustworthiness of detection. The overall system enhances the existing single barcode detection system by a great amount although it is easy to implement and use.

  10. Multi-scale occupancy estimation and modelling using multiple detection methods

    USGS Publications Warehouse

    Nichols, J.D.; Bailey, L.L.; O'Connell, A.F., Jr.; Talancy, N.W.; Grant, E.H.C.; Gilbert, A.T.; Annand, E.M.; Husband, T.P.; Hines, J.E.

    2008-01-01

    1. Occupancy estimation and modelling based on detection?nondetection data provide an effective way of exploring change in a species' distribution across time and space in cases where the species is not always detected with certainty. Today, many monitoring programmes target multiple species, or life stages within a species, requiring the use of multiple detection methods. When multiple methods or devices are used at the same sample sites, animals can be detected by more than one method. 2. We develop occupancy models for multiple detection methods that permit simultaneous use of data from all methods for inference about method-specific detection probabilities. Moreover, the approach permits estimation of occupancy at two spatial scales: the larger scale corresponds to species' use of a sample unit, whereas the smaller scale corresponds to presence of the species at the local sample station or site. 3. We apply the models to data collected on two different vertebrate species: striped skunks Mephitis mephitis and red salamanders Pseudotriton ruber. For striped skunks, large-scale occupancy estimates were consistent between two sampling seasons. Small-scale occupancy probabilities were slightly lower in the late winter/spring when skunks tend to conserve energy, and movements are limited to males in search of females for breeding. There was strong evidence of method-specific detection probabilities for skunks. As anticipated, large- and small-scale occupancy areas completely overlapped for red salamanders. The analyses provided weak evidence of method-specific detection probabilities for this species. 4. Synthesis and applications. Increasingly, many studies are utilizing multiple detection methods at sampling locations. The modelling approach presented here makes efficient use of detections from multiple methods to estimate occupancy probabilities at two spatial scales and to compare detection probabilities associated with different detection methods. The models can

  11. Fast and Accurate Detection of Multiple Quantitative Trait Loci

    PubMed Central

    Nettelblad, Carl; Holmgren, Sverker

    2013-01-01

    Abstract We present a new computational scheme that enables efficient and reliable quantitative trait loci (QTL) scans for experimental populations. Using a standard brute-force exhaustive search effectively prohibits accurate QTL scans involving more than two loci to be performed in practice, at least if permutation testing is used to determine significance. Some more elaborate global optimization approaches, for example, DIRECT have been adopted earlier to QTL search problems. Dramatic speedups have been reported for high-dimensional scans. However, since a heuristic termination criterion must be used in these types of algorithms, the accuracy of the optimization process cannot be guaranteed. Indeed, earlier results show that a small bias in the significance thresholds is sometimes introduced. Our new optimization scheme, PruneDIRECT, is based on an analysis leading to a computable (Lipschitz) bound on the slope of a transformed objective function. The bound is derived for both infinite- and finite-size populations. Introducing a Lipschitz bound in DIRECT leads to an algorithm related to classical Lipschitz optimization. Regions in the search space can be permanently excluded (pruned) during the optimization process. Heuristic termination criteria can thus be avoided. Hence, PruneDIRECT has a well-defined error bound and can in practice be guaranteed to be equivalent to a corresponding exhaustive search. We present simulation results that show that for simultaneous mapping of three QTLS using permutation testing, PruneDIRECT is typically more than 50 times faster than exhaustive search. The speedup is higher for stronger QTL. This could be used to quickly detect strong candidate eQTL networks. PMID:23919387

  12. FPGA-based entropy neural processor for online detection of multiple combined faults on induction motors

    NASA Astrophysics Data System (ADS)

    Cabal-Yepez, E.; Valtierra-Rodriguez, M.; Romero-Troncoso, R. J.; Garcia-Perez, A.; Osornio-Rios, R. A.; Miranda-Vidales, H.; Alvarez-Salas, R.

    2012-07-01

    For industry, a faulty induction motor signifies production reduction and cost increase. Real-world induction motors can have one or more faults present at the same time that can mislead to a wrong decision about its operational condition. The detection of multiple combined faults is a demanding task, difficult to accomplish even with computing intensive techniques. This work introduces information entropy and artificial neural networks for detecting multiple combined faults by analyzing the 3-axis startup vibration signals of the rotating machine. A field programmable gate array implementation is developed for automatic online detection of single and combined faults in real time.

  13. MOTIFSIM: A web tool for detecting similarity in multiple DNA motif datasets.

    PubMed

    Tran, Ngoc Tam L; Huang, Chun-Hsi

    2015-07-01

    Currently, there are a number of motif detection tools available that possess unique functionality. These tools often report different motifs, and therefore use of multiple tools is generally advised since common motifs reported by multiple tools are more likely to be biologically significant. However, results produced by these different tools need to be compared and existing similarity detection tools only allow comparison between two data sets. Here, we describe a motif similarity detection tool (MOTIFSIM) possessing a web-based, user-friendly interface that is capable of detecting similarity from multiple DNA motif data sets concurrently. Results can either be viewed online or downloaded. Users may also download and run MOTIFSIM as a command-line tool in stand-alone mode. The web tool, along with its command-line version, user manuals, and source codes, are freely available at http://biogrid-head.engr.uconn.edu/motifsim/. PMID:26156781

  14. Stereo vision-based pedestrian detection using multiple features for automotive application

    NASA Astrophysics Data System (ADS)

    Lee, Chung-Hee; Kim, Dongyoung

    2015-12-01

    In this paper, we propose a stereo vision-based pedestrian detection using multiple features for automotive application. The disparity map from stereo vision system and multiple features are utilized to enhance the pedestrian detection performance. Because the disparity map offers us 3D information, which enable to detect obstacles easily and reduce the overall detection time by removing unnecessary backgrounds. The road feature is extracted from the v-disparity map calculated by the disparity map. The road feature is a decision criterion to determine the presence or absence of obstacles on the road. The obstacle detection is performed by comparing the road feature with all columns in the disparity. The result of obstacle detection is segmented by the bird's-eye-view mapping to separate the obstacle area which has multiple objects into single obstacle area. The histogram-based clustering is performed in the bird's-eye-view map. Each segmented result is verified by the classifier with the training model. To enhance the pedestrian recognition performance, multiple features such as HOG, CSS, symmetry features are utilized. In particular, the symmetry feature is proper to represent the pedestrian standing or walking. The block-based symmetry feature is utilized to minimize the type of image and the best feature among the three symmetry features of H-S-V image is selected as the symmetry feature in each pixel. ETH database is utilized to verify our pedestrian detection algorithm.

  15. A novel algorithm for detecting multiple covariance and clustering of biological sequences.

    PubMed

    Shen, Wei; Li, Yan

    2016-01-01

    Single genetic mutations are always followed by a set of compensatory mutations. Thus, multiple changes commonly occur in biological sequences and play crucial roles in maintaining conformational and functional stability. Although many methods are available to detect single mutations or covariant pairs, detecting non-synchronous multiple changes at different sites in sequences remains challenging. Here, we develop a novel algorithm, named Fastcov, to identify multiple correlated changes in biological sequences using an independent pair model followed by a tandem model of site-residue elements based on inter-restriction thinking. Fastcov performed exceptionally well at harvesting co-pairs and detecting multiple covariant patterns. By 10-fold cross-validation using datasets of different scales, the characteristic patterns successfully classified the sequences into target groups with an accuracy of greater than 98%. Moreover, we demonstrated that the multiple covariant patterns represent co-evolutionary modes corresponding to the phylogenetic tree, and provide a new understanding of protein structural stability. In contrast to other methods, Fastcov provides not only a reliable and effective approach to identify covariant pairs but also more powerful functions, including multiple covariance detection and sequence classification, that are most useful for studying the point and compensatory mutations caused by natural selection, drug induction, environmental pressure, etc. PMID:27451921

  16. A novel algorithm for detecting multiple covariance and clustering of biological sequences

    PubMed Central

    Shen, Wei; Li, Yan

    2016-01-01

    Single genetic mutations are always followed by a set of compensatory mutations. Thus, multiple changes commonly occur in biological sequences and play crucial roles in maintaining conformational and functional stability. Although many methods are available to detect single mutations or covariant pairs, detecting non-synchronous multiple changes at different sites in sequences remains challenging. Here, we develop a novel algorithm, named Fastcov, to identify multiple correlated changes in biological sequences using an independent pair model followed by a tandem model of site-residue elements based on inter-restriction thinking. Fastcov performed exceptionally well at harvesting co-pairs and detecting multiple covariant patterns. By 10-fold cross-validation using datasets of different scales, the characteristic patterns successfully classified the sequences into target groups with an accuracy of greater than 98%. Moreover, we demonstrated that the multiple covariant patterns represent co-evolutionary modes corresponding to the phylogenetic tree, and provide a new understanding of protein structural stability. In contrast to other methods, Fastcov provides not only a reliable and effective approach to identify covariant pairs but also more powerful functions, including multiple covariance detection and sequence classification, that are most useful for studying the point and compensatory mutations caused by natural selection, drug induction, environmental pressure, etc. PMID:27451921

  17. Vascular ring

    MedlinePlus

    ... with aberrant subclavian and left ligamentum ateriosus; Congenital heart defect - vascular ring; Birth defect heart - vascular ring ... accounts for less than 1% of all congenital heart problems. The condition occurs as often in males ...

  18. Multiple resonance fiber-optic sensor with time division multiplexing for multianalyte detection.

    PubMed

    Lin, Hsing-Ying; Huang, Chen-Han; Huang, Chia-Chi; Liu, Yu-Chia; Chau, Lai-Kwan

    2012-10-01

    A proof-of-concept multiwindow fiber-optic sensor utilizing multiple particle plasmon resonance (PPR) of silver nanoparticles and gold nanorods separately on two unclad portions of the fiber for multianalyte detection is demonstrated. The detection is based on intensity interrogation of multiple wavelengths by a single detector. Time division multiplexing is employed to modulate the illumination of dual-wavelength LEDs to induce PPRs for simultaneous real-time and label-free monitoring of two types of biomolecular interactions. Preliminary results reveal that a refractive index resolution of 9 ×10(-6) RIU is achieved. Moreover, the measured intensities of two windows independently respond to their respective binding events. The potential of the sensor architecture with multiple sensing windows for cascaded, higher throughput, and multianalyte biochemical detection can be expected. PMID:23027248

  19. A handheld device for simultaneous detection of electrical and mechanical cardio-vascular activities with synchronized ECG and CW-Doppler radar.

    PubMed

    Muehlsteff, J; Thijs, J; Pinter, R; Morren, G; Muesch, G

    2007-01-01

    This paper presents a handheld miniaturized sensor embodiment that allows simultaneous measurement of the electrical and related mechanical cardio-vascular activity. Mechanical motion is detected with a continuous wave Doppler radar sensor and interpreted with a synchronously detected ECG. The patient's posture and activity is measured using accelerometers. Challenges of the current technical approach are the positioning of the sensors, the influence of posture and the correct interpretation of the signals. The Doppler signals are compared with phonocardiography measurements, with a focus on the challenges of this technique. There is still research in an improved modeling of the sensor setup and signal interpretation required. PMID:18003321

  20. [A case of hepatocellular carcinoma with multiple lymph node metastases detected by FDG-PET].

    PubMed

    Ito, Tadao; Noguchi, Akinori; Shimizu, Takeshi; Tani, Naoki; Yamaguchi, Masahide; Okano, Shinji; Yamane, Tetsuro; Kawabata, Kenji

    2012-11-01

    We report a case of hepatocellular carcinoma (HCC) with multiple lymph node (LN) metastases. A 68-year-old man underwent hepatectomy at our hospital. Intrahepatic recurrence and swelling of multiple LNs were detected by enhanced CT 21 months later. FDG-PET was positive for multiple swollen LNs, but all were negative for the intrahepatic recurrences. Biopsy of para-aortic LNs was revealed LN metastases from HCC. Immunohistochemically, the LN metastases were composed of poorly differentiated HCC. The sensitivity of FDG-PET in patients with HCC varies in relation to degree of differentiation and decreased FDG uptake must be noted. PMID:23132040

  1. Fault Detection of Railway Vehicle Suspension Systems Using Multiple-Model Approach

    NASA Astrophysics Data System (ADS)

    Hayashi, Yusuke; Tsunashima, Hitoshi; Marumo, Yoshitaka

    This paper demonstrates the possibility to detect suspension failures of railway vehicles using a multiple-model approach from on-board measurement data. The railway vehicle model used includes the lateral and yaw motions of the wheelsets and bogie, and the lateral motion of the vehicle body, with sensors measuring the lateral acceleration and yaw rate of the bogie, and lateral acceleration of the body. The detection algorithm is formulated based on the Interacting Multiple-Model (IMM) algorithm. The IMM method has been applied for detecting faults in vehicle suspension systems in a simulation study. The mode probabilities and states of vehicle suspension systems are estimated based on a Kalman Filter (KF). This algorithm is evaluated in simulation examples. Simulation results indicate that the algorithm effectively detects on-board faults of railway vehicle suspension systems.

  2. Immunoblot Method To Detect Streptococcus pneumoniae and Identify Multiple Serotypes from Nasopharyngeal Secretions

    PubMed Central

    Bronsdon, Melinda A.; O'Brien, Katherine L.; Facklam, Richard R.; Whitney, Cynthia G.; Schwartz, Benjamin; Carlone, George M.

    2004-01-01

    Conventional culture techniques are limited in the ability to detect multiple Streptococcus pneumoniae serotypes in nasopharyngeal (NP) secretions. We developed an immunoblot (IB) method with monoclonal antibodies (MAbs) to detect S. pneumoniae and to identify serotypes. NP specimens stored in skim milk-tryptone-glucose-glycerol medium were assessed by the IB method and the reference culture method (RM). In the RM, four optochin-sensitive alpha-hemolytic colonies resembling pneumococci were typed by the Quellung reaction. In the IB method, a nitrocellulose membrane blot of surface growth was reacted with a pneumococcal surface adhesion (PsaA) MAb and visualized. Of 47 NP specimens, 32 (68%) were found to be positive and 13 (28%) were found to be negative for pneumococci by both methods; each method alone yielded one positive result. The sensitivity and specificity of the IB method for the detection of pneumococci were 97 and 93%, respectively. To identify serotypes, blots were tested with serotype-specific MAbs (4, 6A, 6B, 9V, 14, 18C, 19F, and 23F). To detect the remaining serotypes, positive serotype-specific replicate blots were compared visually to an original anti-PsaA-positive blot; four unidentified colonies were subcultured and serotyped by the Quellung reaction. Fifty-eight S. pneumoniae-positive NP specimens containing 69 pneumococcal strains (23 serotypes) were tested; 68 (98.6%) of the strains were detected by the IB method, and 66 (95.6%) were detected by the RM. For 11 specimens found to contain two serotypes, both methods detected both serotypes in 7 (63.6%), the IB method alone detected the two serotypes in 3 (27.3%), and the RM alone detected both serotypes in 1 (9%). The IB method identified multiple clones and minor populations of pneumococci in NP secretions. This method is useful for detecting specific serotypes and carriage of multiple serotypes in epidemiologic surveillance and carriage studies. PMID:15071010

  3. Biologically inspired multilevel approach for multiple moving targets detection from airborne forward-looking infrared sequences.

    PubMed

    Li, Yansheng; Tan, Yihua; Li, Hang; Li, Tao; Tian, Jinwen

    2014-04-01

    In this paper, a biologically inspired multilevel approach for simultaneously detecting multiple independently moving targets from airborne forward-looking infrared (FLIR) sequences is proposed. Due to the moving platform, low contrast infrared images, and nonrepeatability of the target signature, moving targets detection from FLIR sequences is still an open problem. Avoiding six parameter affine or eight parameter planar projective transformation matrix estimation of two adjacent frames, which are utilized by existing moving targets detection approaches to cope with the moving infrared camera and have become the bottleneck for the further elevation of the moving targets detection performance, the proposed moving targets detection approach comprises three sequential modules: motion perception for efficiently extracting motion cues, attended motion views extraction for coarsely localizing moving targets, and appearance perception in the local attended motion views for accurately detecting moving targets. Experimental results demonstrate that the proposed approach is efficient and outperforms the compared state-of-the-art approaches. PMID:24695135

  4. Stilbene 5c, A Microtubule Poison with Vascular Disrupting Properties That Induces Multiple Modes of Growth Arrest and Cell Death

    PubMed Central

    Alotaibi, M.R.; Asnake, B.; Xu, Di; Beckman, M.J.; Durrant, D; Simoni, D; Baruchello, R; Lee, R. M.; Schwartz, E.L.; Gewirtz, D.A.

    2013-01-01

    The stilbene derivative, cis-3, 4’, 5-trimethoxy-3’-aminostilbene (stilbene 5c), is a potentially potent antitumor agent that acts via binding to the colchicine-binding site in tubulin. The current studies were designed to investigate the effectiveness of stilbene 5c against the HCT-116 human colon cancer cell line and B16/F10 melanoma cells as well as human endothelial cell formation and tumor perfusion. Stilbene 5c produced a time-dependent decrease in cell viability in both cell lines and the capacity of the cells to proliferate was not restored upon removal of the drug. Treatment with stilbene 5c also promoted both senescence and autophagy in both cell lines. TUNEL and annexin 5 staining indicated that apoptosis also occurs in stilbene 5c-treated HCT-116 cells, but not in B16/F10 melanoma cells. DAPI staining revealed morphological changes in the cell nuclei (binucleated and micronucleated cells) indicative of mitotic catastrophe in HCT-116 cells but not in the B16/F10 melanoma cells. p53-null HCT-116 cells demonstrated a similar growth arrest/cell death response to stilbene as p53-wild type HCT-116 cells. Stilbene 5c also completely inhibited human endothelial cell tube formation on Matrigel, consistent with potential anti-angiogenic actions. Using a new method developed for monitoring the pharmacodynamic effects of stilbene 5c in vivo, we found that a single injection of stilbene 5c reduced tumor perfusion by 65% at 4 hours, returning to baseline by 24 hours, while subsequent daily injections of stilbene 5c produced progressively larger reductions and smaller rebounds. This work indicates that stilbene 5c could potentially be effective against melanoma and colon cancer through the promotion of multiple modes of growth arrest and cell death coupled with anti-angiogenic and antivascular actions. PMID:24144631

  5. Stilbene 5c, a microtubule poison with vascular disrupting properties that induces multiple modes of growth arrest and cell death.

    PubMed

    Alotaibi, M R; Asnake, B; Di, Xu; Beckman, M J; Durrant, D; Simoni, D; Baruchello, R; Lee, R M; Schwartz, E L; Gewirtz, D A

    2013-12-15

    The stilbene derivative, cis-3,4',5-trimethoxy-3'-aminostilbene (stilbene 5c), is a potentially potent antitumor agent that acts via binding to the colchicine-binding site in tubulin. The current studies were designed to investigate the effectiveness of stilbene 5c against the HCT-116 human colon cancer cell line and B16/F10 melanoma cells as well as human endothelial cell tube formation and tumor perfusion. Stilbene 5c produced a time-dependent decrease in cell viability in both cell lines and the capacity of the cells to proliferate was not restored upon removal of the drug. Treatment with stilbene 5c also promoted both senescence and autophagy in both cell lines. TUNEL and annexin 5 staining indicated that apoptosis also occurs in stilbene 5c-treated HCT-116 cells, but not in B16/F10 melanoma cells. DAPI staining revealed morphological changes in the cell nuclei (binucleated and micronucleated cells) indicative of mitotic catastrophe in HCT-116 cells but not in the B16/F10 melanoma cells. p53-null HCT-116 cells demonstrated a similar growth arrest/cell death response to stilbene as p53-wild type HCT-116 cells. Stilbene 5c also completely inhibited human endothelial cell tube formation on Matrigel, consistent with potential anti-angiogenic actions. Using a new method developed for monitoring the pharmacodynamic effects of stilbene 5c in vivo, we found that a single injection of stilbene 5c reduced tumor perfusion by 65% at 4h, returning to baseline by 24h, while subsequent daily injections of stilbene 5c produced progressively larger reductions and smaller rebounds. This work indicates that stilbene 5c could potentially be effective against melanoma and colon cancer through the promotion of multiple modes of growth arrest and cell death coupled with anti-angiogenic and antivascular actions. PMID:24144631

  6. Unsupervised Anomaly Detection Based on Clustering and Multiple One-Class SVM

    NASA Astrophysics Data System (ADS)

    Song, Jungsuk; Takakura, Hiroki; Okabe, Yasuo; Kwon, Yongjin

    Intrusion detection system (IDS) has played an important role as a device to defend our networks from cyber attacks. However, since it is unable to detect unknown attacks, i.e., 0-day attacks, the ultimate challenge in intrusion detection field is how we can exactly identify such an attack by an automated manner. Over the past few years, several studies on solving these problems have been made on anomaly detection using unsupervised learning techniques such as clustering, one-class support vector machine (SVM), etc. Although they enable one to construct intrusion detection models at low cost and effort, and have capability to detect unforeseen attacks, they still have mainly two problems in intrusion detection: a low detection rate and a high false positive rate. In this paper, we propose a new anomaly detection method based on clustering and multiple one-class SVM in order to improve the detection rate while maintaining a low false positive rate. We evaluated our method using KDD Cup 1999 data set. Evaluation results show that our approach outperforms the existing algorithms reported in the literature; especially in detection of unknown attacks.

  7. Simultaneous detection of multiple adulterants in dry milk using macro-scale Raman chemical imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential of Raman chemical imaging for simultaneously detecting multiple adulterants in milk powder was investigated. Potential chemical adulterants, including ammonium sulfate, dicyandiamide, melamine, and urea, were mixed together into skim dry milk in the concentration range of 0.1–5.0% for ...

  8. DIF Detection Using Multiple-Group Categorical CFA with Minimum Free Baseline Approach

    ERIC Educational Resources Information Center

    Chang, Yu-Wei; Huang, Wei-Kang; Tsai, Rung-Ching

    2015-01-01

    The aim of this study is to assess the efficiency of using the multiple-group categorical confirmatory factor analysis (MCCFA) and the robust chi-square difference test in differential item functioning (DIF) detection for polytomous items under the minimum free baseline strategy. While testing for DIF items, despite the strong assumption that all…

  9. Automatic Analysis of Retinal Vascular Parameters for Detection of Diabetes in Indian Patients with No Retinopathy Sign.

    PubMed

    Aliahmad, Behzad; Kumar, Dinesh Kant; Jain, Rajeev

    2016-01-01

    This study has investigated the association between retinal vascular parameters with type II diabetes in Indian population with no observable diabetic retinopathy. It has introduced two new retinal vascular parameters: total number of branching angles (TBA) and average acute branching angles (ABA) as potential biomarkers of diabetes in an explanatory model. A total number of 180 retinal images (two (left and right) × two (ODC and MC) × 45 subjects (13 diabetics and 32 nondiabetics)) were analysed. Stepwise linear regression analysis was performed to model the association between type II diabetes with the best subset of explanatory variables (predictors), consisting of retinal vascular parameters and patients' demographic information. P value of the estimated coefficients (P < 0.001) indicated that, at α level of 0.05, the newly introduced retinal vascular parameters, that is, TBA and ABA together with CRAE, mean tortuosity, SD of branching angle, and VB, are related to type II diabetes when there is no observable sign of retinopathy. PMID:27579347

  10. Automatic Analysis of Retinal Vascular Parameters for Detection of Diabetes in Indian Patients with No Retinopathy Sign

    PubMed Central

    Jain, Rajeev

    2016-01-01

    This study has investigated the association between retinal vascular parameters with type II diabetes in Indian population with no observable diabetic retinopathy. It has introduced two new retinal vascular parameters: total number of branching angles (TBA) and average acute branching angles (ABA) as potential biomarkers of diabetes in an explanatory model. A total number of 180 retinal images (two (left and right) × two (ODC and MC) × 45 subjects (13 diabetics and 32 nondiabetics)) were analysed. Stepwise linear regression analysis was performed to model the association between type II diabetes with the best subset of explanatory variables (predictors), consisting of retinal vascular parameters and patients' demographic information. P value of the estimated coefficients (P < 0.001) indicated that, at α level of 0.05, the newly introduced retinal vascular parameters, that is, TBA and ABA together with CRAE, mean tortuosity, SD of branching angle, and VB, are related to type II diabetes when there is no observable sign of retinopathy. PMID:27579347

  11. On the Radio Detection of Multiple-exomoon Systems due to Plasma Torus Sharing

    NASA Astrophysics Data System (ADS)

    Noyola, J. P.; Satyal, S.; Musielak, Z. E.

    2016-04-01

    The idea of single exomoon detection due to the radio emissions caused by its interaction with the host exoplanet is extended to multiple-exomoon systems. The characteristic radio emissions are made possible in part by plasma from the exomoon’s own ionosphere. In this work, it is demonstrated that neighboring exomoons and the exoplanetary magnetosphere could also provide enough plasma to generate a detectable signal. In particular, the plasma-torus-sharing phenomenon is found to be particularly well suited to facilitate the radio detection of plasma-deficient exomoons. The efficiency of this process is evaluated, and the predicted power and frequency of the resulting radio signals are presented.

  12. Plasma Levels of Osteopontin and Vascular Endothelial Growth Factor in Association with Clinical Features and Parameters of Tumor Burden in Patients with Multiple Myeloma

    PubMed Central

    Valković, Toni; Babarović, Emina; Lučin, Ksenija; Štifter, Sanja; Aralica, Merica; Pećanić, Sanja; Seili-Bekafigo, Irena; Duletić-Načinović, Antica; Nemet, Damir; Jonjić, Nives

    2014-01-01

    The aim of this pilot study was to determine the plasma levels of osteopontin (OPN) and vascular endothelial growth factor (VEGF) and find possible association between them and main clinical features and parameters of tumor burden in patient with multiple myeloma (MM). Plasma levels of OPN and VEGF were determined in 44 newly diagnosed MM patients and 24 healthy persons by ELISA method. These values were compared with the presence of anemia, renal dysfunction, and bone lesions as myeloma related clinical manifestations and with serum beta-2 microglobulin and Durie-Salmon clinical stage as prognosticators related to tumor mass. The value of OPN was significantly higher in MM patients with evident bone lesions (P = 0.03) and there was also a positive correlation with serum beta-2 microglobulin (r = 0.366; P = 0.04). Furthermore, patients with lower Durie-Salmon stage had significantly lower OPN and VEGF levels (P = 0.05; P = 0.04, resp.). Our preliminary results found positive association between plasma level of OPN, tumor burden, and bone destruction. Further analysis should provide information about the possible use of OPN as useful clinical biomarker for monitoring bone disease and tumor mass, as well as a prognostic factor, or a possible target for pharmacological intervention. PMID:24995304

  13. Targeting Vascular Endothelial Growth Factor Receptor 2 and Protein Kinase D1 Related Pathways by a Multiple Kinase Inhibitor in Angiogenesis and Inflammation Related Processes In Vitro

    PubMed Central

    Varga, Attila; Gyulavári, Pál; Greff, Zoltán; Futosi, Krisztina; Németh, Tamás; Simon-Szabó, Laura; Kerekes, Krisztina; Szántai-Kis, Csaba; Brauswetter, Diána; Kokas, Márton; Borbély, Gábor; Erdei, Anna; Mócsai, Attila; Kéri, György; Vántus, Tibor

    2015-01-01

    Emerging evidence suggests that the vascular endothelial growth factor receptor 2 (VEGFR2) and protein kinase D1 (PKD1) signaling axis plays a critical role in normal and pathological angiogenesis and inflammation related processes. Despite all efforts, the currently available therapeutic interventions are limited. Prior studies have also proved that a multiple target inhibitor can be more efficient compared to a single target one. Therefore, development of novel inflammatory pathway-specific inhibitors would be of great value. To test this possibility, we screened our molecular library using recombinant kinase assays and identified the previously described compound VCC251801 with strong inhibitory effect on both VEGFR2 and PKD1. We further analyzed the effect of VCC251801 in the endothelium-derived EA.hy926 cell line and in different inflammatory cell types. In EA.hy926 cells, VCC251801 potently inhibited the intracellular activation and signaling of VEGFR2 and PKD1 which inhibition eventually resulted in diminished cell proliferation. In this model, our compound was also an efficient inhibitor of in vitro angiogenesis by interfering with endothelial cell migration and tube formation processes. Our results from functional assays in inflammatory cellular models such as neutrophils and mast cells suggested an anti-inflammatory effect of VCC251801. The neutrophil study showed that VCC251801 specifically blocked the immobilized immune-complex and the adhesion dependent TNF-α -fibrinogen stimulated neutrophil activation. Furthermore, similar results were found in mast cell degranulation assay where VCC251801 caused significant reduction of mast cell response. In summary, we described a novel function of a multiple kinase inhibitor which strongly inhibits the VEGFR2-PKD1 signaling and might be a novel inhibitor of pathological inflammatory pathways. PMID:25874616

  14. Asymmetric signal amplification for simultaneous SERS detection of multiple cancer markers with significantly different levels.

    PubMed

    Ye, Sujuan; Wu, Yanying; Zhai, Xiaomo; Tang, Bo

    2015-08-18

    Simultaneous detection of cancer biomarkers holds great promise for the early diagnosis of different cancers. However, in the presence of high-concentration biomarkers, the signals of lower-expression biomarkers are overlapped. Existing techniques are not suitable for simultaneously detecting multiple biomarkers at concentrations with significantly different orders of magnitude. Here, we propose an asymmetric signal amplification method for simultaneously detecting multiple biomarkers with significantly different levels. Using the bifunctional probe, a linear amplification mode responds to high-concentration markers, and quadratic amplification mode responds to low-concentration markers. With the combined biobarcode probe and hybridization chain reaction (HCR) amplification method, the detection limits of microRNA (miRNA) and ATP via surface-enhanced Raman scattering (SERS) detection are 0.15 fM and 20 nM, respectively, with a breakthrough of detection concentration difference over 11 orders of magnitude. Furthermore, successful determination of miRNA and ATP in cancer cells supports the practicability of the assay. This methodology promises to open an exciting new avenue for the detection of various types of biomolecules. PMID:26218034

  15. Sensitive detection of multiple mycotoxins by SPRi with gold nanoparticles as signal amplification tags.

    PubMed

    Hu, Weihua; Chen, Hongming; Zhang, Huanhuan; He, Guangli; Li, Xin; Zhang, Xiaoxing; Liu, Yang; Li, Chang Ming

    2014-10-01

    Detection of multiple toxic mycotoxins is of importance in food quality control. Surface plasmon resonance imaging (SPRi) is an advanced tool for simultaneously multiple detections with accuracy; however, it suffers from limited sensitivity due to the instrumental constraint and small sizes of mycotoxins with only one epitope for an insensitive competitive immunoassay. In this work a gold nanoparticle (AuNP)-enhanced SPRi chip is designed to sensitively detect multiple mycotoxins using a competitive immunoassay format. The sensing surface is constructed by uniformly attaching dense mycotoxin antigens on poly[oligo(ethylene glycol) methacrylate-co-glycidyl methacrylate] (POEGMA-co-GMA) brush modified SPRi gold chip. After competitive binding in a sample solution containing respective monoclonal antibodies, secondary antibody-conjugated AuNPs are employed to bind with the captured monoclonal antibodies for further amplification of the SPRi signal. Highly specific and sensitive simultaneous detection is achieved for three typical mycotoxins including Aflatoxin B1 (AFB1), Ochratoxin A (OTA) and Zearalenone (ZEN) with low detection limits of 8, 30 and 15 pg mL(-1) and dynamic ranges covering three orders of magnitude. PMID:24992296

  16. Implications of Vascular Aging

    PubMed Central

    Barodka, Viachaslau M.; Joshi, Brijen L.; Berkowitz, Dan E.; Hogue, Charles W.; Nyhan, Daniel

    2011-01-01

    Chronological age is a well established risk factor for the development of cardiovascular diseases. The changes that accumulate in the vasculature with age, though, are highly variable. It is now increasingly recognized that indices of vascular health are more reliable than age per se in predicting adverse cardiovascular outcomes. The variation in the accrual of these age-related vascular changes is a function of multiple genetic and environmental factors. In this review, we highlight some of the pathophysiological mechanisms that characterize the vascular aging phenotype. Furthermore, we provide an overview of the key outcome studies that address the value of these vascular health indices in general and discuss potential effects on perioperative cardiovascular outcomes. PMID:21474663

  17. Estimation of the Performance of Multiple Active Neutron Interrogation Signatures for Detecting Shielded HEU

    SciTech Connect

    David L. Chichester; Scott J. Thompson; Scott M. Watson; James T. Johnson; Edward H. Seabury

    2012-10-01

    A comprehensive modeling study has been carried out to evaluate the utility of multiple active neutron interrogation signatures for detecting shielded highly enriched uranium (HEU). The modeling effort focused on varying HEU masses from 1 kg to 20 kg; varying types of shields including wood, steel, cement, polyethylene, and borated polyethylene; varying depths of the HEU in the shields, and varying engineered shields immediately surrounding the HEU including steel, tungsten, and cadmium. Neutron and gamma-ray signatures were the focus of the study and false negative detection probabilities versus measurement time were used as a performance metric. To facilitate comparisons among different approaches an automated method was developed to generate receiver operating characteristic (ROC) curves for different sets of model variables for multiple background count rate conditions. This paper summarizes results or the analysis, including laboratory benchmark comparisons between simulations and experiments. The important impact engineered shields can play towards degrading detectability and methods for mitigating this will be discussed.

  18. Balancing precision and risk: should multiple detection methods be analyzed separately in N-mixture models?

    PubMed

    Graves, Tabitha A; Royle, J Andrew; Kendall, Katherine C; Beier, Paul; Stetz, Jeffrey B; Macleod, Amy C

    2012-01-01

    Using multiple detection methods can increase the number, kind, and distribution of individuals sampled, which may increase accuracy and precision and reduce cost of population abundance estimates. However, when variables influencing abundance are of interest, if individuals detected via different methods are influenced by the landscape differently, separate analysis of multiple detection methods may be more appropriate. We evaluated the effects of combining two detection methods on the identification of variables important to local abundance using detections of grizzly bears with hair traps (systematic) and bear rubs (opportunistic). We used hierarchical abundance models (N-mixture models) with separate model components for each detection method. If both methods sample the same population, the use of either data set alone should (1) lead to the selection of the same variables as important and (2) provide similar estimates of relative local abundance. We hypothesized that the inclusion of 2 detection methods versus either method alone should (3) yield more support for variables identified in single method analyses (i.e. fewer variables and models with greater weight), and (4) improve precision of covariate estimates for variables selected in both separate and combined analyses because sample size is larger. As expected, joint analysis of both methods increased precision as well as certainty in variable and model selection. However, the single-method analyses identified different variables and the resulting predicted abundances had different spatial distributions. We recommend comparing single-method and jointly modeled results to identify the presence of individual heterogeneity between detection methods in N-mixture models, along with consideration of detection probabilities, correlations among variables, and tolerance to risk of failing to identify variables important to a subset of the population. The benefits of increased precision should be weighed against

  19. Balancing precision and risk: should multiple detection methods be analyzed separately in N-mixture models?

    USGS Publications Warehouse

    Graves, Tabitha A.; Royle, J. Andrew; Kendall, Katherine C.; Beier, Paul; Stetz, Jeffrey B.; Macleod, Amy C.

    2012-01-01

    Using multiple detection methods can increase the number, kind, and distribution of individuals sampled, which may increase accuracy and precision and reduce cost of population abundance estimates. However, when variables influencing abundance are of interest, if individuals detected via different methods are influenced by the landscape differently, separate analysis of multiple detection methods may be more appropriate. We evaluated the effects of combining two detection methods on the identification of variables important to local abundance using detections of grizzly bears with hair traps (systematic) and bear rubs (opportunistic). We used hierarchical abundance models (N-mixture models) with separate model components for each detection method. If both methods sample the same population, the use of either data set alone should (1) lead to the selection of the same variables as important and (2) provide similar estimates of relative local abundance. We hypothesized that the inclusion of 2 detection methods versus either method alone should (3) yield more support for variables identified in single method analyses (i.e. fewer variables and models with greater weight), and (4) improve precision of covariate estimates for variables selected in both separate and combined analyses because sample size is larger. As expected, joint analysis of both methods increased precision as well as certainty in variable and model selection. However, the single-method analyses identified different variables and the resulting predicted abundances had different spatial distributions. We recommend comparing single-method and jointly modeled results to identify the presence of individual heterogeneity between detection methods in N-mixture models, along with consideration of detection probabilities, correlations among variables, and tolerance to risk of failing to identify variables important to a subset of the population. The benefits of increased precision should be weighed against

  20. Spinal focal lesion detection in multiple myeloma using multimodal image features

    NASA Astrophysics Data System (ADS)

    Fränzle, Andrea; Hillengass, Jens; Bendl, Rolf

    2015-03-01

    Multiple myeloma is a tumor disease in the bone marrow that affects the skeleton systemically, i.e. multiple lesions can occur in different sites in the skeleton. To quantify overall tumor mass for determining degree of disease and for analysis of therapy response, volumetry of all lesions is needed. Since the large amount of lesions in one patient impedes manual segmentation of all lesions, quantification of overall tumor volume is not possible until now. Therefore development of automatic lesion detection and segmentation methods is necessary. Since focal tumors in multiple myeloma show different characteristics in different modalities (changes in bone structure in CT images, hypointensity in T1 weighted MR images and hyperintensity in T2 weighted MR images), multimodal image analysis is necessary for the detection of focal tumors. In this paper a pattern recognition approach is presented that identifies focal lesions in lumbar vertebrae based on features from T1 and T2 weighted MR images. Image voxels within bone are classified using random forests based on plain intensities and intensity value derived features (maximum, minimum, mean, median) in a 5 x 5 neighborhood around a voxel from both T1 and T2 weighted MR images. A test data sample of lesions in 8 lumbar vertebrae from 4 multiple myeloma patients can be classified at an accuracy of 95% (using a leave-one-patient-out test). The approach provides a reasonable delineation of the example lesions. This is an important step towards automatic tumor volume quantification in multiple myeloma.

  1. Real-time multiple plane area detection using a self-organizing map

    NASA Astrophysics Data System (ADS)

    Kim, Jeong-Hyun; Teng, Zhu; Kang, Dong-Joong

    2012-01-01

    Plane detection in 3-D space is a core function of the autonomous mobile robot. A representative technique for plane detection is the Hough transform method. The Hough transform is robust to noise and makes accurate plane detection possible. However, a common problem in methods based on the Hough transform is that too much time is required to calculate parameters, which adds computational cost and memory requirements for parameter voting to find the distribution of mixed multiple planes in the parameter space. Furthermore, real-time processing for sequential image sequences is challenging, because the whole process must be repetitively performed for the next detection. We extend the conventional self-organizing map by introducing a real-time clustering method and by detecting multiple planes through the creation, extinction, renewal, and merging of plane parameter data, which are input sequentially. The proposed method is also based on reliable plane detection through a planarity evaluation during data sampling. The results of experiments conducted under various conditions with an unmanned vehicle demonstrate that the proposed method is more accurate and faster than conventional methods.

  2. Indium-111-labeled leukocyte scan in detection of synthetic vascular graft infection: The effect of antibiotic treatment

    SciTech Connect

    Chung, C.J.; Hicklin, O.A.; Payan, J.M.; Gordon, L. )

    1991-01-01

    To determine the sensitivity and specificity of the indium-111-({sup 111}In) labeled leukocyte scan for prosthetic vascular graft infection in patients treated with antibiotic therapy, a retrospective study was performed. Of 41 consecutive {sup 111}In-labeled leukocyte scans performed to evaluate possible vascular graft infection, 23 scans were performed in patients treated with antibiotics. The average duration of antibiotic therapy was 21 days. Twelve positive and 11 negative scans for graft infection were found. By surgical and autopsy correlation of all positive cases, and clinical correlation (of all negative cases), there were 10 true-positive, 11 true-negative, 2 false-positive, and no false-negative scans for graft infections, for an overall sensitivity of 100% and specificity of 85%.

  3. In-situ detection of multiple pathogenic bacteria on food surfaces

    NASA Astrophysics Data System (ADS)

    Chai, Yating; Horikawa, Shin; Hu, Jiajia; Chen, I.-Hsuan; Hu, Jing; Barbaree, James M.; Chin, Bryan A.

    2015-05-01

    Real-time in-situ detection of pathogenic bacteria on fresh food surfaces was accomplished with phage-based magnetoelastic (ME) biosensors. The ME biosensor is constructed of a small rectangular strip of ME material that is coated with a biomolecular recognition element (phage, antibodies or proteins, etc.) that is specific to the target pathogen. This mass-sensitive ME biosensor is wirelessly actuated into mechanical resonance by an externally applied time-varying magnetic field. When the biosensor binds with target bacteria, the mass of the sensor increases, resulting in a decrease in the sensor's resonant frequency. In order to compensate for nonspecific binding, control biosensors without phage were used in this experiment. In previous research, the biosensors were measured one by one. However, the simultaneous measurement of multiple sensors was accomplished in this research, and promises to greatly shorten the analysis time for bacterial detection. Additionally, the use of multiple biosensors enables the possibility of simultaneous detection of different pathogenic bacteria. This paper presents results of experiments in which multiple phage-based ME biosensors were simultaneously monitored. The E2 phage and JRB7 phage from a landscape phage library served as the bio-recognition element that have the capability of binding specifically with Salmonella typhimurium and B. anthracis spores, respectively. Real-time in-situ detection of Salmonella typhimurium and B. anthracis spores on food surfaces are presented.

  4. The 2006 William Feinberg lecture: shifting the paradigm from stroke to global vascular risk estimation.

    PubMed

    Sacco, Ralph L

    2007-06-01

    By the year 2010, it is estimated that 18.1 million people worldwide will die annually because of cardiovascular diseases and stroke. "Global vascular risk" more broadly includes the multiple overlapping disease silos of stroke, myocardial infarction, peripheral arterial disease, and vascular death. Estimation of global vascular risk requires consideration of a variety of variables including demographics, environmental behaviors, and risk factors. Data from multiple studies suggest continuous linear relationships between the physiological vascular risk modulators of blood pressure, lipids, and blood glucose rather than treating these conditions as categorical risk factors. Constellations of risk factors may be more relevant than individual categorical components. Exciting work with novel risk factors may also have predictive value in estimates of global vascular risk. Advances in imaging have led to the measurement of subclinical conditions such as carotid intima-media thickness and subclinical brain conditions such as white matter hyperintensities and silent infarcts. These subclinical measurements may be intermediate stages in the transition from asymptomatic to symptomatic vascular events, appear to be associated with the fundamental vascular risk factors, and represent opportunities to more precisely quantitate disease progression. The expansion of studies in molecular epidemiology and detection of genetic markers underlying vascular risks also promises to extend our precision of global vascular risk estimation. Global vascular risk estimation will require quantitative methods that bundle these multi-dimensional data into more precise estimates of future risk. The power of genetic information coupled with data on demographics, risk-inducing behaviors, vascular risk modulators, biomarkers, and measures of subclinical conditions should provide the most realistic approximation of an individual's future global vascular risk. The ultimate public health benefit

  5. Vascular Streak Dieback of cacao in Southeast Asia detection and Melanesia: in planta detection of the pathogen and a new taxonomy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vascular Streak Dieback (VSD) disease of cacao (Theobroma cacao) in Southeast Asia and Melanesia is caused by a basidiomycete (Ceratobasidiales) fungus described in a monotypic genus as Oncobasidium theobromae (syn. =Thanatephorus theobromae). The symptoms of the disease include green-spotted chloro...

  6. Network hydraulics inclusion in water quality event detection using multiple sensor stations data.

    PubMed

    Oliker, Nurit; Ostfeld, Avi

    2015-09-01

    Event detection is one of the current most challenging topics in water distribution systems analysis: how regular on-line hydraulic (e.g., pressure, flow) and water quality (e.g., pH, residual chlorine, turbidity) measurements at different network locations can be efficiently utilized to detect water quality contamination events. This study describes an integrated event detection model which combines multiple sensor stations data with network hydraulics. To date event detection modelling is likely limited to single sensor station location and dataset. Single sensor station models are detached from network hydraulics insights and as a result might be significantly exposed to false positive alarms. This work is aimed at decreasing this limitation through integrating local and spatial hydraulic data understanding into an event detection model. The spatial analysis complements the local event detection effort through discovering events with lower signatures by exploring the sensors mutual hydraulic influences. The unique contribution of this study is in incorporating hydraulic simulation information into the overall event detection process of spatially distributed sensors. The methodology is demonstrated on two example applications using base runs and sensitivity analyses. Results show a clear advantage of the suggested model over single-sensor event detection schemes. PMID:25996752

  7. Detecting single-target changes in multiple object tracking: The case of peripheral vision.

    PubMed

    Vater, Christian; Kredel, Ralf; Hossner, Ernst-Joachim

    2016-05-01

    In the present study, we investigated whether peripheral vision can be used to monitor multiple moving objects and to detect single-target changes. For this purpose, in Experiment 1, a modified multiple object tracking (MOT) setup with a large projection screen and a constant-position centroid phase had to be checked first. Classical findings regarding the use of a virtual centroid to track multiple objects and the dependency of tracking accuracy on target speed could be successfully replicated. Thereafter, the main experimental variations regarding the manipulation of to-be-detected target changes could be introduced in Experiment 2. In addition to a button press used for the detection task, gaze behavior was assessed using an integrated eyetracking system. The analysis of saccadic reaction times in relation to the motor response showed that peripheral vision is naturally used to detect motion and form changes in MOT, because saccades to the target often occurred after target-change offset. Furthermore, for changes of comparable task difficulties, motion changes are detected better by peripheral vision than are form changes. These findings indicate that the capabilities of the visual system (e.g., visual acuity) affect change detection rates and that covert-attention processes may be affected by vision-related aspects such as spatial uncertainty. Moreover, we argue that a centroid-MOT strategy might reduce saccade-related costs and that eyetracking seems to be generally valuable to test the predictions derived from theories of MOT. Finally, we propose implications for testing covert attention in applied settings. PMID:26942770

  8. Enabling accurate photodiode detection of multiple optical traps by spatial filtering

    NASA Astrophysics Data System (ADS)

    Ott, Dino; Reihani, S. Nader S.; Oddershede, Lene B.

    2014-09-01

    Dual and multiple beam optical tweezers allow for advanced trapping geometries beyond single traps, however, these increased manipulation capabilities, usually complicate the detection of position and force. The accuracy of position and force measurements is often compromised by crosstalk between the detected signals, this crosstalk leading to a systematic error on the measured forces and distances. In dual-beam optical trapping setups, the two traps are typically orthogonal polarized and crosstalk can be minimized by inserting polarization optics in front of the detector, however, this method is not perfect because of the de-polarization of the trapping beam introduced by the required high numerical aperture optics. Moreover, the restriction to two orthogonal polarisation states limits the number of detectable traps to two. Here, we present an easy-to-implement simple method to efficiently eliminate cross-talk in dual beam setups.1 The technique is based on spatial filtering and is highly compatible with standard back-focal-plane photodiode based detection. The reported method significantly improves the accuracy of force-distance measurements, e.g., of single molecules, hence providing much more scientific value for the experimental efforts. Furthermore, it opens the possibility for fast and simultaneous photodiode based detection of multiple holographically generated optical traps.

  9. Paper and Flexible Substrates as Materials for Biosensing Platforms to Detect Multiple Biotargets

    PubMed Central

    Shafiee, Hadi; Asghar, Waseem; Inci, Fatih; Yuksekkaya, Mehmet; Jahangir, Muntasir; Zhang, Michael H.; Durmus, Naside Gozde; Gurkan, Umut Atakan; Kuritzkes, Daniel R.; Demirci, Utkan

    2015-01-01

    The need for sensitive, robust, portable, and inexpensive biosensing platforms is of significant interest in clinical applications for disease diagnosis and treatment monitoring at the point-of-care (POC) settings. Rapid, accurate POC diagnostic assays play a crucial role in developing countries, where there are limited laboratory infrastructure, trained personnel, and financial support. However, current diagnostic assays commonly require long assay time, sophisticated infrastructure and expensive reagents that are not compatible with resource-constrained settings. Although paper and flexible material-based platform technologies provide alternative approaches to develop POC diagnostic assays for broad applications in medicine, they have technical challenges integrating to different detection modalities. Here, we address the limited capability of current paper and flexible material-based platforms by integrating cellulose paper and flexible polyester films as diagnostic biosensing materials with various detection modalities through the development and validation of new widely applicable electrical and optical sensing mechanisms using antibodies and peptides. By incorporating these different detection modalities, we present selective and accurate capture and detection of multiple biotargets including viruses (Human Immunodeficieny Virus-1), bacteria (Escherichia coli and Staphylococcus aureus), and cells (CD4+ T lymphocytes) from fingerprick volume equivalent of multiple biological specimens such as whole blood, plasma, and peritoneal dialysis effluent with clinically relevant detection and sensitivity. PMID:25743880

  10. A multiplexed device based on tunable nanoshearing for specific detection of multiple protein biomarkers in serum.

    PubMed

    Vaidyanathan, Ramanathan; van Leeuwen, Lara Michelle; Rauf, Sakandar; Shiddiky, Muhammad J A; Trau, Matt

    2015-01-01

    Microfluidic flow based multiplexed devices have gained significant promise in detecting biomarkers in complex biological samples. However, to fully exploit their use in bioanalysis, issues such as (i) low sensitivity and (ii) high levels of nonspecific adsorption of non-target species have to be overcome. Herein, we describe a new multiplexed device for the sensitive detection of multiple protein biomarkers in serum by using an alternating current (ac) electrohydrodynamics (ac-EHD) induced surface shear forces based phenomenon referred to as nanoshearing. The tunable nature (via manipulation of ac field) of these nanoshearing forces can alter the capture performance of the device (e.g., improved fluid transport enhances number of sensor-target collisions). This can also selectively displace weakly (nonspecifically) bound molecules from the electrode surface (i.e., fluid shear forces can be tuned to shear away nonspecific species present in biological samples). Using this approach, we achieved sensitive (100 fg mL(-1)) naked eye detection of multiple protein targets spiked in human serum and a 1000-fold enhancement in comparison to hydrodynamic flow based devices for biomarker detection. We believe that this approach could potentially represent a clinical diagnostic tool that can be integrated into resource-limited settings for sensitive detection of target biomarkers using naked eye. PMID:25978807

  11. A Multiplexed Device Based on Tunable Nanoshearing for Specific Detection of Multiple Protein Biomarkers in Serum

    PubMed Central

    Vaidyanathan, Ramanathan; van Leeuwen, Lara Michelle; Rauf, Sakandar; Shiddiky, Muhammad J. A.; Trau, Matt

    2015-01-01

    Microfluidic flow based multiplexed devices have gained significant promise in detecting biomarkers in complex biological samples. However, to fully exploit their use in bioanalysis, issues such as (i) low sensitivity and (ii) high levels of nonspecific adsorption of non-target species have to be overcome. Herein, we describe a new multiplexed device for the sensitive detection of multiple protein biomarkers in serum by using an alternating current (ac) electrohydrodynamics (ac-EHD) induced surface shear forces based phenomenon referred to as nanoshearing. The tunable nature (via manipulation of ac field) of these nanoshearing forces can alter the capture performance of the device (e.g., improved fluid transport enhances number of sensor-target collisions). This can also selectively displace weakly (nonspecifically) bound molecules from the electrode surface (i.e., fluid shear forces can be tuned to shear away nonspecific species present in biological samples). Using this approach, we achieved sensitive (100 fg mL−1) naked eye detection of multiple protein targets spiked in human serum and a 1000-fold enhancement in comparison to hydrodynamic flow based devices for biomarker detection. We believe that this approach could potentially represent a clinical diagnostic tool that can be integrated into resource-limited settings for sensitive detection of target biomarkers using naked eye. PMID:25978807

  12. Recursive ideal observer detection of known M-ary signals in multiplicative and additive Gaussian noise.

    NASA Technical Reports Server (NTRS)

    Painter, J. H.; Gupta, S. C.

    1973-01-01

    This paper presents the derivation of the recursive algorithms necessary for real-time digital detection of M-ary known signals that are subject to independent multiplicative and additive Gaussian noises. The motivating application is minimum probability of error detection of digital data-link messages aboard civil aircraft in the earth reflection multipath environment. For each known signal, the detector contains one Kalman filter and one probability computer. The filters estimate the multipath disturbance. The estimates and the received signal drive the probability computers. Outputs of all the computers are compared in amplitude to give the signal decision. The practicality and usefulness of the detector are extensively discussed.

  13. Multiple instance dictionary learning for subsurface object detection using handheld EMI

    NASA Astrophysics Data System (ADS)

    Zare, Alina; Cook, Matthew; Alvey, Brendan; Ho, Dominic K.

    2015-05-01

    A dictionary learning approach for subsurface object detection using handheld electromagnetic induction (EMI) data is presented. A large number of unsupervised and supervised dictionary learning methods have been developed in the literature. However, the majority of these methods require data point-specific labels during training. In the application to subsurface object detection, often the specific training data samples that correspond to target and non-target are not known and difficult to determine manually. In this paper, a dictionary learning method that addresses this issue using the multiple instance learning techniques is presented. Results are shown on real EMI data sets.

  14. The expression of osteopontin and vascular endothelial growth factor in correlation with angiogenesis in monoclonal gammopathy of undetermined significance and multiple myeloma.

    PubMed

    Babarović, Emina; Valković, Toni; Budisavljević, Ivana; Balen, Ivan; Štifter, Sanja; Duletić-Načinović, Antica; Lučin, Ksenija; Jonjić, Nives

    2016-06-01

    Several studies have shown a gradual increase in the extent of bone marrow angiogenesis in various stages of proliferative plasma cell disorders, from monoclonal gammopathy of undetermined significance (MGUS) to active multiple myeloma (MM). The main aim of this study was to evaluate tumor angiogenesis parameters in detail and to correlate them with the expression of osteopontin (OPN) and vascular endothelial growth factor (VEGF) in the bone marrow of patients with MGUS and MM. In addition, we wanted to determine their prognostic significance in active MM. Ninety-five patients were enrolled in the study: 14 diagnosed with MGUS, 13 with asymptomatic myeloma (AMM) and 68 with active MM. Computer assisted image analysis was used to determine the angiogenesis parameters, the quantity of microvessels per 1mm(2) (MVD), the area occupied by microvessels per 1mm(2) and the percentage of microvessel area in total section area (TVA). Double immunohistochemical methods CD138+VEGF and CD138+OPN were used to evaluate expression of these proteins in plasma cells, and OPN was also analyzed for its interstitial expression (iOPN). A significant positive correlation was determined between VEGF and iOPN with angiogenic parameters in the MGUS stage of the disease. In advanced stages of the disease, a significant negative correlation was recorded between OPN and iOPN with parameters of angiogenesis. Overall survival was significantly shorter for patients with negative iOPN (p=0.002) and higher angiogenic parameters, MVD (p=0.009), TVA (p=0.008) and area of microvessels per 1mm(2) (p=0.02). Positive VEGF expression in our model predicted a better three-year survival of patients with active MM (OR: 5.25, p=0.03; HR: 0.44, p=0.04). The results of our study suggested a possible key role of VEGF and OPN in the induction of angiogenesis in early-stage disease. PMID:26997492

  15. Effects of aliskiren, a renin inhibitor, on biomarkers of platelet activity, coagulation and fibrinolysis in subjects with multiple risk factors for vascular disease.

    PubMed

    Serebruany, V L; Malinin, A; Barsness, G; Vahabi, J; Atar, D

    2008-05-01

    Aliskiren, an octanamide, is nonpeptide, low molecular weight, orally active renin inhibitor effectively preventing angiotensin and aldosterone release. This drug has been recently approved for the treatment of hypertension. Considering potential links between hypertension, platelets, the coagulation cascade and fibrinolysis we sought to evaluate the effect of aliskiren on human biomarkers of hemostasis. In vitro effects of whole blood preincubation with escalating concentrations of aliskiren (500, 1,000 and 2,000 ng ml(-1)) were assessed in 20 aspirin-naive volunteers with multiple risk factors for vascular disease. A total of 33 biomarkers were measured, of which 18 are related to platelet function, 12 to coagulation and 3 to fibrinolysis. Pretreatment of blood samples with aliskiren 500 ng ml(-1) resulted in a significant increase of antithrombin-III (AT-III) activity (P=0.003). All other tested biomarkers were not significantly affected. Spiking whole blood with the higher aliskiren doses was associated with various trends in biomarker activity, where 1000 ng ml(-1) concentration mostly decreased (7/33), and 2,000 ng ml(-1) mostly increased (6/33) some biomarkers. In the therapeutic concentration of 500 ng ml(-1) aliskiren does not affect hemostatic biomarkers, except for a moderate but highly significant (P=0.003) increase of AT-III activity. Higher aliskiren doses were associated with more profound biomarker changes, but they are likely not to be clinically relevant since they show diverging (that is, both mild antiplatelet and platelet-activating) trends, and considering the 2- to 4-fold safety margin. It is suggested that antithrombotic properties of aliskiren be explored further in an ex vivo clinical setting. PMID:18273042

  16. Detection of multiple tumor markers using ultra-long carbon nanotube devices

    NASA Astrophysics Data System (ADS)

    So, Hye-Mi; Park, Dong-Won; Kim, Beom Soo; Kong, Ki-Jeong; Buh, Gyoung-Ho; Chang, Hyunju; Lee, Jeong-O.; Kong, Jing

    2008-03-01

    For the simultaneous detection of multiple tumor markers, we have fabricated ultra-long carbon nanotube sensors that can detect carcinoembryonic antigen (CEA) and prostate specific antigen (PSA), simultaneously. Ultra-long carbon nanotubes, several millimeters long, were grown by ethanol CVD, and fabricated as FET sensors by using conventional photolithography. To functionalize each segment of a single ultra-long nanotube device with multiple-tumor markers, we first functionalize the entire device with CDI-Tween 20 linking molecules, and then immobilized CEA and PSA antibodies using the microfluidic channel. The electrical conductance from CEA-antibody functionalized and PSA-antibody functionalized segment of a ultra-long carbon nanotube device was monitored simultaneously with Ag/AgCl reference electrode as a liquid gate. We will discuss the advantages of long-nanotube device in detail.

  17. Three-dimensional fluorescent microscopy via simultaneous illumination and detection at multiple planes

    PubMed Central

    Ma, Qian; Khademhosseinieh, Bahar; Huang, Eric; Qian, Haoliang; Bakowski, Malina A.; Troemel, Emily R.; Liu, Zhaowei

    2016-01-01

    The conventional optical microscope is an inherently two-dimensional (2D) imaging tool. The objective lens, eyepiece and image sensor are all designed to capture light emitted from a 2D ‘object plane’. Existing technologies, such as confocal or light sheet fluorescence microscopy have to utilize mechanical scanning, a time-multiplexing process, to capture a 3D image. In this paper, we present a 3D optical microscopy method based upon simultaneously illuminating and detecting multiple focal planes. This is implemented by adding two diffractive optical elements to modify the illumination and detection optics. We demonstrate that the image quality of this technique is comparable to conventional light sheet fluorescent microscopy with the advantage of the simultaneous imaging of multiple axial planes and reduced number of scans required to image the whole sample volume. PMID:27527813

  18. Detection, localization and classification of multiple dipole-like magnetic sources using magnetic gradient tensor data

    NASA Astrophysics Data System (ADS)

    Gang, Yin; Yingtang, Zhang; Hongbo, Fan; Zhining, Li; Guoquan, Ren

    2016-05-01

    We have developed a method for automatic detection, localization and classification (DLC) of multiple dipole sources using magnetic gradient tensor data. First, we define modified tilt angles to estimate the approximate horizontal locations of the multiple dipole-like magnetic sources simultaneously and detect the number of magnetic sources using a fixed threshold. Secondly, based on the isotropy of the normalized source strength (NSS) response of a dipole, we obtain accurate horizontal locations of the dipoles. Then the vertical locations are calculated using magnitude magnetic transforms of magnetic gradient tensor data. Finally, we invert for the magnetic moments of the sources using the measured magnetic gradient tensor data and forward model. Synthetic and field data sets demonstrate effectiveness and practicality of the proposed method.

  19. Three-dimensional fluorescent microscopy via simultaneous illumination and detection at multiple planes.

    PubMed

    Ma, Qian; Khademhosseinieh, Bahar; Huang, Eric; Qian, Haoliang; Bakowski, Malina A; Troemel, Emily R; Liu, Zhaowei

    2016-01-01

    The conventional optical microscope is an inherently two-dimensional (2D) imaging tool. The objective lens, eyepiece and image sensor are all designed to capture light emitted from a 2D 'object plane'. Existing technologies, such as confocal or light sheet fluorescence microscopy have to utilize mechanical scanning, a time-multiplexing process, to capture a 3D image. In this paper, we present a 3D optical microscopy method based upon simultaneously illuminating and detecting multiple focal planes. This is implemented by adding two diffractive optical elements to modify the illumination and detection optics. We demonstrate that the image quality of this technique is comparable to conventional light sheet fluorescent microscopy with the advantage of the simultaneous imaging of multiple axial planes and reduced number of scans required to image the whole sample volume. PMID:27527813

  20. Simultaneous detection of multiple chemical residues in milk using broad-specifity antibodies in a hybrid immunosorbent assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wide array of applications using quantum dots (QDs) for detection of multiple analytes reflects the versatility of the technology. In this study, a novel immunoassay using 2 types of sensors (QDs and an enzyme) were simultaneously used for detecting multiple structurally different low-molecular...

  1. Template reporter bacteriophage platform and multiple bacterial detection assays based thereon

    NASA Technical Reports Server (NTRS)

    Goodridge, Lawrence (Inventor)

    2007-01-01

    The invention is a method for the development of assays for the simultaneous detection of multiple bacteria. A bacteria of interest is selected. A host bacteria containing plasmid DNA from a T even bacteriophage that infects the bacteria of interest is infected with T4 reporter bacteriophage. After infection, the progeny bacteriophage are plating onto the bacteria of interest. The invention also includes single-tube, fast and sensitive assays which utilize the novel method.

  2. Extensive skeletal involvement detected by gallium-67 citrate in a patient with multiple myeloma

    SciTech Connect

    Nishiyama, H.; Morand, T.M.; Seiwert, V.J.

    1988-03-01

    Extensive skeletal involvement of multiple myeloma was detected by Ga-67 citrate imaging while searching for infectious foci. The case was unique in that a radiographic skeletal survey showed typical lytic lesions only in the skull, and extensive myeloma involvement in the skeletal system was an incidental finding. A high tumor cell burden was presumed to be present, which led to a rapid and fulminant clinical course in this patient.

  3. Single- and multiple-pulse noncoherent detection statistics associated with partially developed speckle.

    PubMed

    Osche, G R

    2000-08-20

    Single- and multiple-pulse detection statistics are presented for aperture-averaged direct detection optical receivers operating against partially developed speckle fields. A partially developed speckle field arises when the probability density function of the received intensity does not follow negative exponential statistics. The case of interest here is the target surface that exhibits diffuse as well as specular components in the scattered radiation. An approximate expression is derived for the integrated intensity at the aperture, which leads to single- and multiple-pulse discrete probability density functions for the case of a Poisson signal in Poisson noise with an additive coherent component. In the absence of noise, the single-pulse discrete density function is shown to reduce to a generalized negative binomial distribution. The radar concept of integration loss is discussed in the context of direct detection optical systems where it is shown that, given an appropriate set of system parameters, multiple-pulse processing can be more efficient than single-pulse processing over a finite range of the integration parameter n. PMID:18350006

  4. Simultaneous and spatially separated detection of multiple orbital angular momentum states

    NASA Astrophysics Data System (ADS)

    Tudor, R.; Mihailescu, M.; Kusko, C.; Paun, I. A.; Nan, A. E.; Kusko, M.

    2016-06-01

    We present a method for spatially separated detection of multiple orbital angular momentum (OAM) states, simultaneous. The starting point is the generation of axially superposed Laguerre-Gauss beams, carrying multiple OAM states using a single computer generated hologram. The information contained in the OAM superposition is transferred to the first diffraction order and is detected at the receiver with a reading mask, which contains two perpendicular superposed fork-like holograms, ensuring the spatial separation of the OAM states. The dynamic of the process is studied in terms of the number of generated OAM states and the constructive parameters values. The experimental investigations use an optical arrangement based on a spatial light modulator in the transmitter unit and an amplitude mask in the receiver unit. This proof of concept experiment demonstrates the possibility of simultaneously detection of multiple OAM states in points located at different coordinates, controlled through the design of the holograms and shows the capability of our proposed method to increase the capacity of free-space optical communication channels.

  5. Autofluorescence detection using UV diode laser simultaneous excitation of multiple wavelengths

    NASA Astrophysics Data System (ADS)

    Wilson, Geoffrey A.; DeFreez, Richard K.

    2003-09-01

    America faces the threat of biological attack. Stopping such attacks requires the fast detection of pathogens. Fluorescence of key biological substances provides a real-time technique for detecting airborne pathogens. Pacific Scientific Instruments has already demonstrated that Bioni, a bio-aerosol sensor based on a CW UV-emitting AlGaN diode laser, can detect within seconds the dispersal of threat organisms in postal sorting facilities and other settings. Minimization of false positives is especially important in bio-threat detection, since false positives can lead to undue public alarm, stoppages of work, and costly clean-ups. Although Bioni has proven itself as a fast and sensitive trigger, its selectivity is limited by its single-wavelength excitation and single-band fluorescence detection. In this paper, we describe the development of BioLert, which uses simultaneous excitation and detection at multiple wavelengths to improve specificity and guard against false positives. Initial experimental results on the detection of individual spores of Bacillus globigii (BG), as well as discrimination against inert aerosols, will be discussed.

  6. Comparison of Superb Micro-Vascular Ultrasound Imaging (SMI) and Contrast-Enhanced Ultrasound (CEUS) for Detection of Endoleaks After Endovascular Aneurysm Repair (EVAR)

    PubMed Central

    Gabriel, Marcin; Tomczak, Jolanta; Snoch-Ziółkiewicz, Magdalena; Dzieciuchowicz, Łukasz; Strauss, Ewa; Oszkinis, Grzegorz

    2016-01-01

    Patient: Male, 68 Final Diagnosis: Unusual clinical course Symptoms: None Medication: — Clinical Procedure: Angio CT Specialty: Surgery Objective: Challenging differential diagnosis Background: High-resolution contrast-enhanced ultrasound is one of methods used in the detection and characterization of endoleaks, which is a frequent complication after EVAR. A new technology provided by Toshiba’s AplioTM 500 ultrasound system, called Superb Micro-Vascular Imaging (SMI), is dedicated specifically to imaging very low flow states and appears to be a promising new method for detection of endoleaks. Case Report: After endovascular treatment, a 68-year-old patient who had stent-graft implantation underwent clinical examinations, including contrast-enhanced ultrasound (CEUS), superb micro-vascular imaging (SMI), and computed tomographic angiography (CTA), revealing additional information about abnormal blood flow localized in the periphery of the sack of the left common iliac artery aneurysm. By using CEUS and SMI, the endoleak was clearly visible. Conclusions: This case report illustrates the potential clinical value of this advanced Doppler technology (SMI) and how it could influence clinical management. PMID:26806053

  7. Resistive-Pulse Measurements with Nanopipettes: Detection of Vascular Endothelial Growth Factor C (VEGF-C) Using Antibody-Decorated Nanoparticles

    PubMed Central

    Cai, Huijing; Wang, Yixian; Yu, Yun; Mirkin, Michael V.; Bhakta, Snehasis; Bishop, Gregory W.; Joshi, Amit A.; Rusling, James F.

    2015-01-01

    Quartz nanopipettes have recently been employed for resistive-pulse sensing of Au nanoparticles (AuNP) and nanoparticles with bound antibodies. The analytical signal in such experiments is the change in ionic current caused by the nanoparticle translocation through the pipette orifice. This paper describes resistive-pulse detection of cancer biomarker (Vascular Endothelial Growth Factor-C, VEGF-C) through the use of antibody-modified AuNPs and nanopipettes. The main challenge was to differentiate between AuNPs with attached antibodies for VEGF-C and antigen-conjugated particles. The zeta-potentials of these types of particles are not very different, and, therefore, carefully chosen pipettes with well-characterized geometry were necessary for selective detection of VEGF-C. PMID:26040997

  8. Vascular rings.

    PubMed

    Backer, Carl L; Mongé, Michael C; Popescu, Andrada R; Eltayeb, Osama M; Rastatter, Jeffrey C; Rigsby, Cynthia K

    2016-06-01

    The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time. PMID:27301603

  9. Ultrasensitive detection and rapid identification of multiple foodborne pathogens with the naked eyes.

    PubMed

    Zhang, Heng; Zhang, Yali; Lin, Yankui; Liang, Tongwen; Chen, Zhihua; Li, Jinfeng; Yue, Zhenfeng; Lv, Jingzhang; Jiang, Qing; Yi, Changqing

    2015-09-15

    In this study, a novel approach for ultrasensitive detection and rapid high-throughput identification of a panel of common foodborne pathogens with the naked eyes is presented. As a proof-of-concept application, a multiple pathogen analysis array is fabricated through immobilizing three specific polyT-capture probes which can respectively recognize rfbE gene (Escherichia coli O157:H7), invA gene (Salmonella enterica), inlA gene (Listeria monocytogenes) on the plastic substrates. PCR has been developed for amplification and labeling target genes of rfbE, invA, inlA with biotin. The biotinated target DNA is then captured onto the surface of plastic strips through specific DNA hybridization. The succeeding staining of biotinated DNA duplexes with avidin-horseradish peroxidise (AV-HRP) and biotinated anti-HRP antibody greatly amplifies the detectable signal through the multiple cycle signal amplification strategy, and thus realizing ultrasensitive and specific detection of the above three pathogens in food samples with the naked eyes. Results showed approximately 5 copies target pathogenic DNA could be detected with the naked eyes. This simple but very efficient colorimetric assay also show excellent anti-interference capability and good stability, and can be readily applied to point-of-care diagnosis. PMID:25909338

  10. Construction of customized redundant multiwavelet via increasing multiplicity for fault detection of rotating machinery

    NASA Astrophysics Data System (ADS)

    Chen, Jinglong; Zuo, Ming J.; Zi, Yanyang; He, Zhengjia

    2014-01-01

    Fault detection from the vibration measurement data of rotating machinery is significant for avoiding serious accidents. However, non-stationary vibration signal with a large amount of noise makes this task challenging. Multiwavelet not only owns the advantage on multi-resolution analysis but also can offer multiple wavelet basis functions. So it has the possibility of detecting various fault features preferably. However, the fixed basis functions which are not related to the given signal may lower the accuracy of fault detection. Moreover, another major intrinsic deficiency of multiwavelet lies in its critically sampled filter-bank, which causes shift-variance and is harmful to extract the feature of periodical impulses. To overcome these deficiencies, a new method called customized redundant multiwavelet (CRM) is constructed via increasing multiplicity (IM). IM is a simple method to design a series of changeable multiwavelet which are available for the subsequent optimization process. By the rule of the envelope spectrum entropy minimum principle, optimal multiwavelet is searched for. Based on the customized multiwavelet filters, the filters of CRM can be calculated by inserting zeros. The proposed method is applied to analyze the simulation, gearbox and rolling element bearing vibration signals. Compared with some other conventional methods, the results demonstrate that the proposed method possesses robust performance in detecting fault features of rotating machinery.

  11. Vascular Tumors

    PubMed Central

    Sepulveda, Abel; Buchanan, Edward P.

    2014-01-01

    Vascular anomalies are divided into two main groups: tumors and malformations. Vascular tumors are a large and complex group of lesions, especially for clinicians with none or little experience in this field. In the past, these lesions caused a great deal of confusion because many appear analogous to the naked eye. Thankfully, recent advances in diagnostic techniques have helped the medical community to enhance our comprehension, accurately label, diagnose, and treat these lesions. In this article, we will review the most frequent vascular tumors and provide the reader with the tools to properly label, diagnose, and manage these complex lesions. PMID:25045329

  12. An electrochemical molecular recognition-based aptasensor for multiple protein detection.

    PubMed

    Cheng, Lin; Zhang, Jie; Lin, Yan; Wang, Qiong; Zhang, XiuXiu; Ding, YanHua; Cui, Hanfeng; Fan, Hao

    2015-12-15

    This article reports a simple electrochemical approach for the detection of multiple proteins (thrombin and lysozyme) using Dabcyl-labeled aptamer modified metal nanoparticles (DLAPs). DLAPs were immobilized on β-cyclodextrins (β-CDs) modified electrode by means of host-guest self-assembly. During the time of detection, the aptamers' structure will change due to the specific binding with corresponding proteins that forced DLAPs far away from the electrode that had been modified by β-CDs. Thus, the capture of target proteins onto DLAPs was translated via the electrochemical current signal offered by metal nanoparticles. Linearity of the aptasensor for quantitative measurements was demonstrated. Determinations of proteins in human real serum samples were also performed to demonstrate detection in real clinical samples. PMID:26344894

  13. Paper-based upconversion fluorescence resonance energy transfer biosensor for sensitive detection of multiple cancer biomarkers

    NASA Astrophysics Data System (ADS)

    Xu, Sai; Dong, Biao; Zhou, Donglei; Yin, Ze; Cui, Shaobo; Xu, Wen; Chen, Baojiu; Song, Hongwei

    2016-03-01

    A paper-based upconversion fluorescence resonance energy transfer assay device is proposed for sensitive detection of CEA. The device is fabricated on a normal filter paper with simple nano-printing method. Upconversion nanoparticles tagged with specific antibodies are printed to the test zones on the test paper, followed by the introduction of assay antigen. Upconversion fluorescence measurements are directly conducted on the test zones after the antigen-to-antibody reactions. Furthermore, a multi-channel test paper for simultaneous detection of multiple cancer biomarkers was established by the same method and obtained positive results. The device showed high anti-interfere, stability, reproducible and low detection limit (0.89 ng/mL), moreover it is very easy to fabricate and operate, which is a promising prospect for a clinical point-of-care test.

  14. Paper-based upconversion fluorescence resonance energy transfer biosensor for sensitive detection of multiple cancer biomarkers

    PubMed Central

    Xu, Sai; Dong, Biao; Zhou, Donglei; Yin, Ze; Cui, Shaobo; Xu, Wen; Chen, Baojiu; Song, Hongwei

    2016-01-01

    A paper-based upconversion fluorescence resonance energy transfer assay device is proposed for sensitive detection of CEA. The device is fabricated on a normal filter paper with simple nano-printing method. Upconversion nanoparticles tagged with specific antibodies are printed to the test zones on the test paper, followed by the introduction of assay antigen. Upconversion fluorescence measurements are directly conducted on the test zones after the antigen-to-antibody reactions. Furthermore, a multi-channel test paper for simultaneous detection of multiple cancer biomarkers was established by the same method and obtained positive results. The device showed high anti-interfere, stability, reproducible and low detection limit (0.89 ng/mL), moreover it is very easy to fabricate and operate, which is a promising prospect for a clinical point-of-care test. PMID:27001460

  15. Detection of a polynitroaromatic compound using a novel polymer-based multiplate sensor

    NASA Astrophysics Data System (ADS)

    Arbuthnot, Diane; Bartholomew, Dwight U.; Carr, Richard; Elkind, Jerome L.; Gheorghiu, Liliana; Melendez, Jose L.; Seitz, William R.

    1998-09-01

    A novel sensor concept for detection of polynitroaromatic compounds has been developed in a partnership between Texas Instruments and the University of New Hampshire. The objective for this sensor is to demonstrate an explosive detection system designed specifically for field use. Our approach incorporates manufacturability and low cost while emphasizing field compatibility, usability, hand-held portability, selectivity, and sensitivity. The new device incorporates a novel multi-plate configuration and is based on colorimetric changes that occur when polynitroaromatic compounds react with polyvinylchloride polymer films containing Jeffamine T-403. Response time and characteristic absorbance for the films will be presented along with a description of the device. The results represent a first step toward a potential solution for detection of vapors utilizing chemically sensitive optical polymers.

  16. Vascular Diseases

    MedlinePlus

    ... heart and blood vessels, such as diabetes or high cholesterol Smoking Obesity Losing weight, eating healthy foods, being active and not smoking can help vascular disease. Other treatments include medicines and surgery.

  17. Optical Coherence Tomography versus Visual Evoked Potentials in detecting subclinical visual impairment in multiple sclerosis

    PubMed Central

    Grecescu, M

    2014-01-01

    Rationale. Visual impairment is one of the most common clinical manifestations of multiple sclerosis (MS). Some multiple sclerosis patients complain of poor vision although the Snellen visual acuity is 20/20. This study reveals that sensitive measurements like visual evoked potential (VEP) and optical coherence tomography (OCT) can evidence subclinical disturbances of visual pathway. These methods examine the relation between the visual function (VEP) and retinal nerve fiber layer (RNFL) thickness, as a structural biomarker for axonal loss in patients with multiple sclerosis (MS). The findings in this study indicate the utility of combining structural and functional testing in clinical research on patients with MS. Purpose. To detect visual impairment in a population of visually asymptomatic patients affected by clinically definite multiple sclerosis (MS) and to compare the utility of optical coherence tomography (OCT) versus visual evoked potentials (VEP). Material and methods. Fourteen patients (28 eyes) affected by clinically definite MS, without a history of optic neuritis and asymptomatic for visual disturbances, were initially fully examined (visual acuity, ocular fundus, biomicroscopy) from an ophthalmic point of view and then measured by OCT (RNFL thickness) and VEP. Patients with a history of glaucoma or other retinal or optic nerve disease were excluded. Results. Of fourteen patients (28 eyes), VEP was abnormal in 11 cases (78,57%) and OCT (RNFL thickness) was abnormal in 5 cases (35,71%), while 3 patients had no abnormalities on neither tests. Conclusions. Optical coherence tomography (OCT) is less sensitive than visual evoked potentials (VEPs) in detecting visual subclinical impairment in patients with multiple sclerosis (MS). VEP remains the preferred test for the detection of clinical and subclinical optic neuritis. OCT may provide complementary information to VEP in cases with clinical definite MS and represent a valuable research instrument for the

  18. Multiple-Parameter, Low-False-Alarm Fire-Detection Systems

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Greensburg, Paul; McKnight, Robert; Xu, Jennifer C.; Liu, C. C.; Dutta, Prabir; Makel, Darby; Blake, D.; Sue-Antillio, Jill

    2007-01-01

    Fire-detection systems incorporating multiple sensors that measure multiple parameters are being developed for use in storage depots, cargo bays of ships and aircraft, and other locations not amenable to frequent, direct visual inspection. These systems are intended to improve upon conventional smoke detectors, now used in such locations, that reliably detect fires but also frequently generate false alarms: for example, conventional smoke detectors based on the blockage of light by smoke particles are also affected by dust particles and water droplets and, thus, are often susceptible to false alarms. In contrast, by utilizing multiple parameters associated with fires, i.e. not only obscuration by smoke particles but also concentrations of multiple chemical species that are commonly generated in combustion, false alarms can be significantly decreased while still detecting fires as reliably as older smoke-detector systems do. The present development includes fabrication of sensors that have, variously, micrometer- or nanometer-sized features so that such multiple sensors can be integrated into arrays that have sizes, weights, and power demands smaller than those of older macroscopic sensors. The sensors include resistors, electrochemical cells, and Schottky diodes that exhibit different sensitivities to the various airborne chemicals of interest. In a system of this type, the sensor readings are digitized and processed by advanced signal-processing hardware and software to extract such chemical indications of fires as abnormally high concentrations of CO and CO2, possibly in combination with H2 and/or hydrocarbons. The system also includes a microelectromechanical systems (MEMS)-based particle detector and classifier device to increase the reliability of measurements of chemical species and particulates. In parallel research, software for modeling the evolution of a fire within an aircraft cargo bay has been developed. The model implemented in the software can

  19. Use of Quantitative 16S Ribosomal DNA Detection for Diagnosis of Central Vascular Catheter-Associated Bacterial Infection

    PubMed Central

    Warwick, S.; Wilks, M.; Hennessy, E.; Powell-Tuck, J.; Small, M.; Sharp, J.; Millar, M. R.

    2004-01-01

    Many central vascular catheters (CVCs) are removed unnecessarily because current diagnostic methods for CVC-associated infection are unreliable. A quantitative PCR assay using primers and probe targeted to bacterial 16S ribosomal DNA was used to measure the levels of bacterial DNA in blood samples drawn through the CVC in a population of patients receiving intravenous nutrition. Bacterial DNA concentrations were raised in 16 of 16 blood samples taken during episodes of probable bacterial CVC-associated infection. Bacterial DNA concentrations were raised in 4 of 29 episodes in which bacterial CVC-associated infection was unlikely. The use of this technique has the potential to substantially reduce the unnecessary removal of CVCs. PMID:15070980

  20. Detection of Multiple Potato Viruses in the Field Suggests Synergistic Interactions among Potato Viruses in Pakistan.

    PubMed

    Hameed, Amir; Iqbal, Zafar; Asad, Shaheen; Mansoor, Shahid

    2014-12-01

    Viral diseases have been a major limiting factor threating sustainable potato (Solanum tuberosum L.) production in Pakistan. Surveys were conducted to serologically quantify the incidence of RNA viruses infecting potato; Potato virus X (PVX), Potato virus Y (PVY), Potato virus S (PVS), Potato virus A (PVA), Potato virus M (PVM) and Potato leaf roll virus (PLRV) in two major potato cultivars (Desiree and Cardinal). The results suggest the prevalence of multiple viruses in all surveyed areas with PVY, PVS and PVX dominantly widespread with infection levels of up to 50% in some regions. Co-infections were detected with the highest incidence (15.5%) for PVX and PVS. Additionally the data showed a positive correlation between co-infecting viruses with significant increase in absorbance value (virus titre) for at least one of the virus in an infected plant and suggested a synergistic interaction. To test this hypothesis, glasshouse grown potato plants were challenged with multiple viruses and analyzed for systemic infections and symptomology studies. The results obtained conclude that multiple viral infections dramatically increase disease epidemics as compared to single infection and an effective resistance strategy in targeting multiple RNA viruses is required to save potato crop. PMID:25506305

  1. A feasibility study for long-path multiple detection using a neural network

    NASA Technical Reports Server (NTRS)

    Feuerbacher, G. A.; Moebes, T. A.

    1994-01-01

    Least-squares inverse filters have found widespread use in the deconvolution of seismograms and the removal of multiples. The use of least-squares prediction filters with prediction distances greater than unity leads to the method of predictive deconvolution which can be used for the removal of long path multiples. The predictive technique allows one to control the length of the desired output wavelet by control of the predictive distance, and hence to specify the desired degree of resolution. Events which are periodic within given repetition ranges can be attenuated selectively. The method is thus effective in the suppression of rather complex reverberation patterns. A back propagation(BP) neural network is constructed to perform the detection of first arrivals of the multiples and therefore aid in the more accurate determination of the predictive distance of the multiples. The neural detector is applied to synthetic reflection coefficients and synthetic seismic traces. The processing results show that the neural detector is accurate and should lead to an automated fast method for determining predictive distances across vast amounts of data such as seismic field records. The neural network system used in this study was the NASA Software Technology Branch's NETS system.

  2. Application of multiple laboratory tests for Mycobacterium avium ssp. paratuberculosis detection in Crohn's disease patient specimens.

    PubMed

    Banche, Giuliana; Allizond, Valeria; Sostegni, Raffaello; Lavagna, Alessandro; Bergallo, Massimiliano; Sidoti, Francesca; Daperno, Marco; Rocca, Rodolfo; Cuffini, Anna Maria

    2015-07-01

    The difficulties involved in detecting and enumerating Mycobacterium avium subsp. paratuberculosis (MAP) as a pathogen potentially involved in Crohn's disease (CD) are well known. This study aimed to improve this situation through the application of multiple laboratory diagnostic tests to detect and isolate this bacterium from different specimens collected from CD-patients and non-CD subjects as controls. A total of 120 samples (terminal ileum and colon biopsies, blood and stool) were obtained from 19 CD-patients and from 11 individuals who did not have a clinicopathological diagnosis of CD (non-CD controls) attending for ileocolonoscopy. All samples were processed by staining techniques, culture on both solid and liquid media, and Insertion Sequence 900/F57 real-time PCR. The MAP frequency in CD-patients was found in a significantly greater proportion than in non-CD subjects; the most positive samples were biopsies from CD-patients tested by real-time PCR. MAP detection in biopsies, and in the other samples, by applying multiple and validated laboratory diagnostic tests, could be a marker of active infection, supporting MAP involvement in CD. PMID:26147146

  3. Detection improvement using multiple time-reversal guide-sources in shallow water

    NASA Astrophysics Data System (ADS)

    Gaumond, Charles F.; Fromm, David M.

    2002-11-01

    Detection in a monostatic broadband, active sonar system in shallow water is degraded by propagation induced spreading. The method of multiple guide sources has been presented as a method to mitigate this degradation. This paper shows the detection improvement from the use of the separable kernel receiver (SKR) that is based on a statistical behavior of the ensemble of multiple guide-source signals, which provide several one-way propagation signals from guide sources at various ranges at a single depth. A measure of information is derived to quantify the variability of these guide-source signals. The improvement of detection is shown as a function of range and depth for several sets of system and environmental parameters. In particular, two environments are shown. One is the case of farther ranges and lower frequencies in shallow water where the propagation causes dispersion. The other is the case of shorter ranges and higher frequencies in shallow water where the propagation effects are predominantly multipath. [Work supported by ONR.

  4. Rational, modular adaptation of enzyme-free DNA circuits to multiple detection methods

    PubMed Central

    Li, Bingling; Ellington, Andrew D.; Chen, Xi

    2011-01-01

    Signal amplification is a key component of molecular detection. Enzyme-free signal amplification is especially appealing for the development of low-cost, point-of-care diagnostics. It has been previously shown that enzyme-free DNA circuits with signal-amplification capacity can be designed using a mechanism called ‘catalyzed hairpin assembly’. However, it is unclear whether the efficiency and modularity of such circuits is suitable for multiple analytical applications. We have therefore designed and characterized a simplified DNA circuit based on catalyzed hairpin assembly, and applied it to multiple different analytical formats, including fluorescent, colorimetric, and electrochemical and signaling. By optimizing the design of previous hairpin-based catalytic assemblies we found that our circuit has almost zero background and a high catalytic efficiency, with a kcat value above 1 min−1. The inherent modularity of the circuit allowed us to readily adapt our circuit to detect both RNA and small molecule analytes. Overall, these data demonstrate that catalyzed hairpin assembly is suitable for analyte detection and signal amplification in a ‘plug-and-play’ fashion. PMID:21693555

  5. Improved detection of differentially expressed genes in microarray experiments through multiple scanning and image integration

    PubMed Central

    Romualdi, Chiara; Trevisan, Silvia; Celegato, Barbara; Costa, Germano; Lanfranchi, Gerolamo

    2003-01-01

    The variability of results in microarray technology is in part due to the fact that independent scans of a single hybridised microarray give spot images that are not quite the same. To solve this problem and turn it to our advantage, we introduced the approach of multiple scanning and of image integration of microarrays. To this end, we have developed specific software that creates a virtual image that statistically summarises a series of consecutive scans of a microarray. We provide evidence that the use of multiple imaging (i) enhances the detection of differentially expressed genes; (ii) increases the image homogeneity; and (iii) reveals false-positive results such as differentially expressed genes that are detected by a single scan but not confirmed by successive scanning replicates. The increase in the final number of differentially expressed genes detected in a microarray experiment with this approach is remarkable; 50% more for microarrays hybridised with targets labelled by reverse transcriptase, and 200% more for microarrays developed with the tyramide signal amplification (TSA) technique. The results have been confirmed by semi-quantitative RT–PCR tests. PMID:14627839

  6. A method for detecting IBD regions simultaneously in multiple individuals--with applications to disease genetics.

    PubMed

    Moltke, Ida; Albrechtsen, Anders; Hansen, Thomas V O; Nielsen, Finn C; Nielsen, Rasmus

    2011-07-01

    All individuals in a finite population are related if traced back long enough and will, therefore, share regions of their genomes identical by descent (IBD). Detection of such regions has several important applications-from answering questions about human evolution to locating regions in the human genome containing disease-causing variants. However, IBD regions can be difficult to detect, especially in the common case where no pedigree information is available. In particular, all existing non-pedigree based methods can only infer IBD sharing between two individuals. Here, we present a new Markov Chain Monte Carlo method for detection of IBD regions, which does not rely on any pedigree information. It is based on a probabilistic model applicable to unphased SNP data. It can take inbreeding, allele frequencies, genotyping errors, and genomic distances into account. And most importantly, it can simultaneously infer IBD sharing among multiple individuals. Through simulations, we show that the simultaneous modeling of multiple individuals makes the method more powerful and accurate than several other non-pedigree based methods. We illustrate the potential of the method by applying it to data from individuals with breast and/or ovarian cancer, and show that a known disease-causing mutation can be mapped to a 2.2-Mb region using SNP data from only five seemingly unrelated affected individuals. This would not be possible using classical linkage mapping or association mapping. PMID:21493780

  7. A nanoparticle-based sensor for visual detection of multiple mutations

    NASA Astrophysics Data System (ADS)

    Elenis, Dimitrios S.; Ioannou, Penelope C.; Christopoulos, Theodore K.

    2011-04-01

    Disposable dipstick-type DNA biosensors in the form of lateral flow strips are particularly useful for genotyping in a small laboratory or for field testing due to their simplicity, low cost and portability. Their unique advantage is that they enable visual detection in minutes without the use of instruments. In addition, the dry-reagent format minimizes the pipetting, incubation and washing steps. In this work, we significantly enhance the multiplexing capabilities of lateral flow strip biosensors without compromising their simplicity. Multiplex genotyping is carried out by polymerase chain reaction (PCR) followed by a single primer extension reaction for all target alleles, in which a primer is extended and biotin is incorporated only if it is perfectly complementary to the target. Multiallele detection is achieved by multiple test spots on the membrane of the sensor, each comprising a suspension of polystyrene microspheres functionalized with capture probes. The products of the primer extension reaction hybridize, through specific sequence tags, to the capture probes and are visualized by using antibiotin-conjugated gold nanoparticles. This design enables accommodation of multiple spots in a small area because the microspheres are trapped in the fibres of the membrane and remain fixed in site without any diffusion. Furthermore, the detectability is improved because the hybrids are exposed on the surface of the trapped microspheres rather than inside the pores of the membrane. We demonstrate the specificity and performance of the biosensor for multiallele genotyping.

  8. Association of targeted multiplex PCR with resequencing microarray for the detection of multiple respiratory pathogens.

    PubMed

    Shen, Hongwei; Zhu, Bingqing; Wang, Shulian; Mo, Haolian; Wang, Ji; Li, Jin; Zhang, Chen; Zeng, Huashu; Guan, Li; Shi, Weixian; Zhang, Yong; Ma, Xuejun

    2015-01-01

    A large number of viral and bacterial organisms are responsible for community-acquired pneumonia (CAP) which contributes to substantial burden on health management. A new resequencing microarray (RPM-IVDC1) associated with targeted multiplex PCR was recently developed and validated for multiple respiratory viruses detection and discrimination. In this study, we evaluated the capability of RPM-IVDC1 for simultaneous identification of multiple viral and bacterial organisms. The nasopharyngeal aspirates (NPAs) of 110 consecutive CAP patients, aged from 1 month to 96 years old, were collected from five distinct general hospitals in Beijing during 1-year period. The samples were subjected to the RPM-IVDC1 established protocol as compared to a real-time PCR (qRT-PCR), which was used as standard. The results of virus detection were consistent with those previously described. A total of 37 of Streptococcus pneumoniae, 14 of Haemophilus influenzae, 10 of Mycoplasma pneumoniae, two of Klebsiella pneumoniae and one of Moraxella catarrhalis were detected by RPM-IVDC1. The sensitivities and specificities were compared with those of qRT-PCR for S. pneumoniae (100, 100%, respectively), H. influenzae (92.3, 97.9%, respectively), M. pneumoniae (69.2, 99.0%, respectively), K. pneumoniae (100, 100%, respectively), and M. catarrhalis (100, 100%, respectively). Additional 22 of Streptococcus spp., 24 of Haemophilus spp. and 16 of Neisseria spp. were identified. In addition, methicillin-resistant and carbapenemases allele were also found in nine of Staphylococcus spp. and one of K. pneumoniae, respectively. These results demonstrated the capability of RPM-IVDC1 for simultaneous detection of broad-spectrum respiratory pathogens in complex backgrounds and the advantage of accessing to the actual sequences, showing great potential use of epidemic outbreak investigation. The detection results should be carefully interpreted when introducing this technique in the clinical diagnostics. PMID

  9. A method based on iterative morphological filtering and multiple scattering for detecting layer boundaries and extinction coefficients with LIDAR

    NASA Astrophysics Data System (ADS)

    Li, Meng; Jiang, Li-Hui; Xiong, Xing-Long; Ma, Yu-Zhao; Liu, Jie-Sheng

    2016-08-01

    Layer boundaries detection with LIDAR is of great significance for the meteorological and environmental research. Apart from the background noise, multiple scattering can also seriously affect the detection results in LIDAR signal processing. To alleviate these issues, a novel approach was proposed based upon morphological filtering and multiple scattering correction with multiple iterations, which essentially acts as a weighted algorithm with multiple scattering factors in different filtering scales, and applies integral extinction coefficients as media to perform correction. Simulations on artificial signals and real LIDAR signals support this approach.

  10. A method based on iterative morphological filtering and multiple scattering for detecting layer boundaries and extinction coefficients with LIDAR

    NASA Astrophysics Data System (ADS)

    Li, Meng; Jiang, Li-Hui; Xiong, Xing-Long; Ma, Yu-Zhao; Liu, Jie-Sheng

    2016-05-01

    Layer boundaries detection with LIDAR is of great significance for the meteorological and environmental research. Apart from the background noise, multiple scattering can also seriously affect the detection results in LIDAR signal processing. To alleviate these issues, a novel approach was proposed based upon morphological filtering and multiple scattering correction with multiple iterations, which essentially acts as a weighted algorithm with multiple scattering factors in different filtering scales, and applies integral extinction coefficients as media to perform correction. Simulations on artificial signals and real LIDAR signals support this approach.

  11. Statistical Analysis of the Performance of MDL Enumeration for Multiple-Missed Detection in Array Processing

    PubMed Central

    Du, Fei; Li, Yibo; Jin, Shijiu

    2015-01-01

    An accurate performance analysis on the MDL criterion for source enumeration in array processing is presented in this paper. The enumeration results of MDL can be predicted precisely by the proposed procedure via the statistical analysis of the sample eigenvalues, whose distributive properties are investigated with the consideration of their interactions. A novel approach is also developed for the performance evaluation when the source number is underestimated by a number greater than one, which is denoted as “multiple-missed detection”, and the probability of a specific underestimated source number can be estimated by ratio distribution analysis. Simulation results are included to demonstrate the superiority of the presented method over available results and confirm the ability of the proposed approach to perform multiple-missed detection analysis. PMID:26295232

  12. Raman signal enhancement by multiple beam excitation and its application for the detection of chemicals

    SciTech Connect

    Gupta, Sakshi; Ahmad, Azeem; Mehta, Dalip S.; Gambhir, Vijayeta; Reddy, Martha N.

    2015-08-31

    In a typical Raman based sensor, a single laser beam is used for exciting the sample and the backscattered or forward scattered light is collected using collection optics and is analyzed by a spectrometer. We have investigated that by means of exciting the sample with multiple beams, i.e., by dividing the same input power of the single beam into two or three or more beams and exciting the sample from different angles, the Raman signal enhances significantly. Due to the presence of multiple beams passing through the same volume of the sample, an interference pattern is formed and the volume of interaction of excitation beams with the sample increases. By means of this geometry, the enhancement in the Raman signal is observed and it was found that the signal strength increases linearly with the increase in number of excitation beams. Experimental results of this scheme for excitation of the samples are reported for explosive detection at a standoff distance.

  13. Fault detection and isolation for a full-scale railway vehicle suspension with multiple Kalman filters

    NASA Astrophysics Data System (ADS)

    Jesussek, Mathias; Ellermann, Katrin

    2014-12-01

    Reliability and dependability in complex mechanical systems can be improved by fault detection and isolation (FDI) methods. These techniques are key elements for maintenance on demand, which could decrease service cost and time significantly. This paper addresses FDI for a railway vehicle: the mechanical model is described as a multibody system, which is excited randomly due to track irregularities. Various parameters, like masses, spring- and damper-characteristics, influence the dynamics of the vehicle. Often, the exact values of the parameters are unknown and might even change over time. Some of these changes are considered critical with respect to the operation of the system and they require immediate maintenance. The aim of this work is to detect faults in the suspension system of the vehicle. A Kalman filter is used in order to estimate the states. To detect and isolate faults the detection error is minimised with multiple Kalman filters. A full-scale train model with nonlinear wheel/rail contact serves as an example for the described techniques. Numerical results for different test cases are presented. The analysis shows that for the given system it is possible not only to detect a failure of the suspension system from the system's dynamic response, but also to distinguish clearly between different possible causes for the changes in the dynamical behaviour.

  14. US and MRI features in venous vascular malformation of the abdominal wall. A case report

    PubMed Central

    Alessandrino, F.; Maira, A.; Tarantino, C.C.

    2012-01-01

    Vascular anomalies are classified as vascular tumors and vascular malformations. Venous vascular malformations are the most common type of vascular malformation. They may be isolated or multiple and they rarely affect the trunk. The authors report a rare case of isolated venous vascular malformation of the abdominal wall with an emphasis on the related MRI and ultrasound (US) features. PMID:23450707

  15. Detection of bifurcations in noisy coupled systems from multiple time series

    SciTech Connect

    Williamson, Mark S. Lenton, Timothy M.

    2015-03-15

    We generalize a method of detecting an approaching bifurcation in a time series of a noisy system from the special case of one dynamical variable to multiple dynamical variables. For a system described by a stochastic differential equation consisting of an autonomous deterministic part with one dynamical variable and an additive white noise term, small perturbations away from the system's fixed point will decay slower the closer the system is to a bifurcation. This phenomenon is known as critical slowing down and all such systems exhibit this decay-type behaviour. However, when the deterministic part has multiple coupled dynamical variables, the possible dynamics can be much richer, exhibiting oscillatory and chaotic behaviour. In our generalization to the multi-variable case, we find additional indicators to decay rate, such as frequency of oscillation. In the case of approaching a homoclinic bifurcation, there is no change in decay rate but there is a decrease in frequency of oscillations. The expanded method therefore adds extra tools to help detect and classify approaching bifurcations given multiple time series, where the underlying dynamics are not fully known. Our generalisation also allows bifurcation detection to be applied spatially if one treats each spatial location as a new dynamical variable. One may then determine the unstable spatial mode(s). This is also something that has not been possible with the single variable method. The method is applicable to any set of time series regardless of its origin, but may be particularly useful when anticipating abrupt changes in the multi-dimensional climate system.

  16. Multiple tests for wind turbine fault detection and score fusion using two- level multidimensional scaling (MDS)

    NASA Astrophysics Data System (ADS)

    Ye, Xiang; Gao, Weihua; Yan, Yanjun; Osadciw, Lisa A.

    2010-04-01

    Wind is an important renewable energy source. The energy and economic return from building wind farms justify the expensive investments in doing so. However, without an effective monitoring system, underperforming or faulty turbines will cause a huge loss in revenue. Early detection of such failures help prevent these undesired working conditions. We develop three tests on power curve, rotor speed curve, pitch angle curve of individual turbine. In each test, multiple states are defined to distinguish different working conditions, including complete shut-downs, under-performing states, abnormally frequent default states, as well as normal working states. These three tests are combined to reach a final conclusion, which is more effective than any single test. Through extensive data mining of historical data and verification from farm operators, some state combinations are discovered to be strong indicators of spindle failures, lightning strikes, anemometer faults, etc, for fault detection. In each individual test, and in the score fusion of these tests, we apply multidimensional scaling (MDS) to reduce the high dimensional feature space into a 3-dimensional visualization, from which it is easier to discover turbine working information. This approach gains a qualitative understanding of turbine performance status to detect faults, and also provides explanations on what has happened for detailed diagnostics. The state-of-the-art SCADA (Supervisory Control And Data Acquisition) system in industry can only answer the question whether there are abnormal working states, and our evaluation of multiple states in multiple tests is also promising for diagnostics. In the future, these tests can be readily incorporated in a Bayesian network for intelligent analysis and decision support.

  17. Model observer design for detecting multiple abnormalities in anatomical background images

    NASA Astrophysics Data System (ADS)

    Wen, Gezheng; Markey, Mia K.; Park, Subok

    2016-03-01

    As psychophysical studies are resource-intensive to conduct, model observers are commonly used to assess and optimize medical imaging quality. Existing model observers were typically designed to detect at most one signal. However, in clinical practice, there may be multiple abnormalities in a single image set (e.g., multifocal and multicentric breast cancers (MMBC)), which can impact treatment planning. Prevalence of signals can be different across anatomical regions, and human observers do not know the number or location of signals a priori. As new imaging techniques have the potential to improve multiple-signal detection (e.g., digital breast tomosynthesis may be more effective for diagnosis of MMBC than planar mammography), image quality assessment approaches addressing such tasks are needed. In this study, we present a model-observer mechanism to detect multiple signals in the same image dataset. To handle the high dimensionality of images, a novel implementation of partial least squares (PLS) was developed to estimate different sets of efficient channels directly from the images. Without any prior knowledge of the background or the signals, the PLS channels capture interactions between signals and the background which provide discriminant image information. Corresponding linear decision templates are employed to generate both image-level and location-specific scores on the presence of signals. Our preliminary results show that the model observer using PLS channels, compared to our first attempts with Laguerre-Gauss channels, can achieve high performance with a reasonably small number of channels, and the optimal design of the model observer may vary as the tasks of clinical interest change.

  18. RNA aptamer against autoantibodies associated with multiple sclerosis and bioluminescent detection probe on its basis.

    PubMed

    Vorobjeva, Maria A; Krasitskaya, Vasilisa V; Fokina, Alesya A; Timoshenko, Valentina V; Nevinsky, Georgy A; Venyaminova, Alya G; Frank, Ludmila A

    2014-03-01

    Nowadays, there are no specific laboratory tests for establishing the diagnosis of multiple sclerosis (MS). The presence of proteolytic autoantibodies against myelin basic protein is now considered as a characteristic feature of MS. New 2'-F-containing RNA aptamer of high affinity and specificity to these antibodies was selected. Covalent conjugate of this aptamer and Ca(2+)-regulated photoprotein obelin was obtained for the first time and applied as a label in bioluminescent microplate assay to detect target antibodies. The developed model solid-phase microassay is simple, fast, and highly sensitive. PMID:24512542

  19. Detection of multiple blood feeding in Aedes aegypti (Diptera: Culicidae) during a single gonotrophic cycle using a histologic technique.

    PubMed

    Scott, T W; Clark, G G; Lorenz, L H; Amerasinghe, P H; Reiter, P; Edman, J D

    1993-01-01

    We evaluated a histologic technique for its usefulness in detecting multiple blood feeding by Aedes aegypti (L.) in a single gonotrophic cycle. To standardize the procedure, we carried out a laboratory study in which 166 mosquitoes imbibed two blood meals at known intervals. Eighty percent (78/98) of the multiple meals were detected when the interval between meals was from 1 to < to = 24 h and the time from the second meal to fixation ranged from 0 to 12 hr. At intervals outside this range, only 34% (23/68) of the multiple meals were detected. Overall, 61% (101/166) of the double meals were detected. Examination of 96 engorged Ae. aegypti collected by aspiration from inside houses in San Juan, Puerto Rico, indicated that 50% had imbibed multiple meals. Most wild-caught mosquitoes took their last meal the day before capture, and most multiple feeders fed twice on consecutive days. A dark line of digested blood, or heme, around the first meal and a physical separation between meals were the most useful histologic parameters for detecting multiple feeding in wild Ae. aegypti. An association of multiple feeding with advanced stages of oocyte development suggests that, at the time of collection, most Ae. aegypti from the study site had fed twice in each gonotrophic cycle. We conclude that, although it is labor intensive, histologic examination is an appropriate technique for a longitudinal, community-wide survey of multiple feeding by Ae. aegypti. PMID:8433350

  20. Multiple RT-PCR markers for the detection of circulating tumour cells of metastatic canine mammary tumours.

    PubMed

    da Costa, A; Kohn, B; Gruber, A D; Klopfleisch, R

    2013-04-01

    In humans, detection of circulating tumour cells (CTCs) using nucleic acid-based methods such as reverse transcription polymerase chain reaction (RT-PCR) has proven to be of prognostic relevance. However, similar procedures are still lacking in veterinary oncology. To assess the correlation of CTC markers with the metastatic potential of canine mammary tumours, 120 peripheral blood samples from bitches with mammary carcinomas with (group 1) and without (group 2) histological evidence of vascular invasion and/or presence of lymph node metastases and mammary adenomas (group 3) were analyzed. Blood samples were collected in EDTA tubes and RNA was extracted within 48 h. Subsequently, the samples were tested by RT-PCR for a panel of seven CTC mRNA markers. CRYAB was the most sensitive single marker with a sensitivity of 35% and also the most specific marker with a specificity of 100% to detect group 1 blood samples. A multimarker assay combining four genes enhanced the sensitivity up to 77.5%, but decreased the specificity to 80%. CRYAB appeared to be highly specific but only moderately sensitive at detecting blood samples from dogs with metastatic tumours and detection significantly correlated with vascular invasion of primary mammary tumours. However, a multimarker assay of four genes significantly enhanced the sensitivity of the assay and is therefore preferable for CTC detection. PMID:23036177

  1. Vascular trauma in civilian practice.

    PubMed Central

    Golledge, J.; Scriven, M. W.; Fligelstone, L. J.; Lane, I. F.

    1995-01-01

    Vascular trauma is associated with major morbidity and mortality, but little is known about its incidence or nature in Britain. A retrospective study of 36 patients requiring operative intervention for vascular trauma under one vascular surgeon over a 6-year period was undertaken. Twenty-four patients suffered iatrogenic trauma (median age 61 years); including cardiological intervention (19), radiological intervention (2), varicose vein surgery (1), umbilical vein catherisation (1) and isolated hyperthermic limb perfusion (1). There were 23 arterial and three venous injuries. Twelve patients had accidental trauma (median age 23 years). Three of the ten patients with blunt trauma were referred for vascular assessment before orthopaedic intervention, two after an on-table angiogram and five only after an initial orthopaedic procedure (range of delay 6 h to 10 days). Injuries were arterial in nine, venous in two and combined in one. Angiography was obtained in six patients, and in two patients with multiple upper limb fractures identified the site of injury when clinical localisation was difficult. A variety of vascular techniques were used to treat the injuries. Two patients died postoperatively and one underwent major limb amputation. Thirty-two (89%) remain free of vascular sequelae after a median follow-up of 48 months (range 3-72 months). Vascular trauma is uncommon in the United Kingdom. To repair the injuries a limited repertoire of vascular surgery techniques is needed. Therefore, vascular surgical assessment should be sought at an early stage to prevent major limb loss. PMID:8540659

  2. Detection of multiple sclerosis lesions in MRIs with an SVM classifier

    NASA Astrophysics Data System (ADS)

    D'Addabbo, Annarita; Ancona, Nicola; Blonda, Palma N.; De Blasi, Roberto A.

    2003-05-01

    The purpose of this paper is to test the effectiveness of a Support Vector Machine (SVM) classifier, with gaussian kernel function, in the automatic detection of small lesions from Magnetic Resonance Images (MRIs) of a patientt affected by multiple sclerosis. The data set consists of Proton Density, T2 (the spin-spin relaxation time) Spin-Echo images and a three-dimensional T1-weighted gradient echo sequence, called Magnetization-Prepared RApid Gradient Echo, that can be generated from contiguous and very thin sections, allowing detection of small lesions typically affected by partial volume effects and intersection gaps in T1 weighted Spin-Echol sequences. In this context of classification, SVM with Gaussian kernel function exhibited a good classification accuracy, higher than accuracies obtained, on the same data set, with a traditional RBF, confirming its high generalization capability and its effectiveness when applied to low-dimensional multi-spectral images.

  3. Multicolored, Tb³⁺-Based Antibody-Free Detection of Multiple Tyrosine Kinase Activities.

    PubMed

    Lipchik, Andrew M; Perez, Minervo; Cui, Wei; Parker, Laurie L

    2015-08-01

    Kinase signaling is a major mechanism driving many cancers. While many inhibitors have been developed and are employed in the clinic, resistance due to crosstalk and pathway reprogramming is an emerging problem. High-throughput assays to detect multiple pathway kinases simultaneously could better model these complex relationships and enable drug development to combat this type of resistance. We developed a strategy to take advantage of time-resolved luminescence of Tb(3+)-chelated phosphotyrosine-containing peptides, which facilitated efficient energy transfer to small molecule fluorophores conjugated to the peptides to produce orthogonally colored biosensors for two different kinases. This enabled multiplexed detection with high signal-to-noise in a high-throughput-compatible format. This proof-of-concept study provides a platform that could be applied to other lanthanide metal and fluorophore combinations to achieve even greater multiplexing without the need for phosphospecific antibodies. PMID:26207839

  4. A hybrid algorithm for multiple change-point detection in continuous measurements

    NASA Astrophysics Data System (ADS)

    Priyadarshana, W. J. R. M.; Polushina, T.; Sofronov, G.

    2013-10-01

    Array comparative genomic hybridization (aCGH) is one of the techniques that can be used to detect copy number variations in DNA sequences. It has been identified that abrupt changes in the human genome play a vital role in the progression and development of many diseases. We propose a hybrid algorithm that utilizes both the sequential techniques and the Cross-Entropy method to estimate the number of change points as well as their locations in aCGH data. We applied the proposed hybrid algorithm to both artificially generated data and real data to illustrate the usefulness of the methodology. Our results show that the proposed algorithm is an effective method to detect multiple change-points in continuous measurements.

  5. Multiple-Frame Detection of Subpixel Targets in Thermal Image Sequences

    NASA Technical Reports Server (NTRS)

    Thompson, David R.; Kremens, Robert

    2013-01-01

    The new technology in this approach combines the subpixel detection information from multiple frames of a sequence to achieve a more sensitive detection result, using only the information found in the images themselves. It is taken as a constraint that the method is automated, robust, and computationally feasible for field networks with constrained computation and data rates. This precludes simply downloading a video stream for pixel-wise co-registration on the ground. It is also important that this method not require precise knowledge of sensor position or direction, because such information is often not available. It is also assumed that the scene in question is approximately planar, which is appropriate for a high-altitude airborne or orbital view.

  6. Detecting a Weak Association by Testing its Multiple Perturbations: a Data Mining Approach

    NASA Astrophysics Data System (ADS)

    Lo, Min-Tzu; Lee, Wen-Chung

    2014-05-01

    Many risk factors/interventions in epidemiologic/biomedical studies are of minuscule effects. To detect such weak associations, one needs a study with a very large sample size (the number of subjects, n). The n of a study can be increased but unfortunately only to an extent. Here, we propose a novel method which hinges on increasing sample size in a different direction-the total number of variables (p). We construct a p-based `multiple perturbation test', and conduct power calculations and computer simulations to show that it can achieve a very high power to detect weak associations when p can be made very large. As a demonstration, we apply the method to analyze a genome-wide association study on age-related macular degeneration and identify two novel genetic variants that are significantly associated with the disease. The p-based method may set a stage for a new paradigm of statistical tests.

  7. detecting multiple sclerosis lesions with a fully bioinspired visual attention model

    NASA Astrophysics Data System (ADS)

    Villalon-Reina, Julio; Gutierrez-Carvajal, Ricardo; Thompson, Paul M.; Romero-Castro, Eduardo

    2013-11-01

    The detection, segmentation and quantification of multiple sclerosis (MS) lesions on magnetic resonance images (MRI) has been a very active field for the last two decades because of the urge to correlate these measures with the effectiveness of pharmacological treatment. A myriad of methods has been developed and most of these are non specific for the type of lesions and segment the lesions in their acute and chronic phases together. On the other hand, radiologists are able to distinguish between several stages of the disease on different types of MRI images. The main motivation of the work presented here is to computationally emulate the visual perception of the radiologist by using modeling principles of the neuronal centers along the visual system. By using this approach we are able to detect the lesions in the majority of the images in our population sample. This type of approach also allows us to study and improve the analysis of brain networks by introducing a priori information.

  8. Multi-feature-based robust face detection and coarse alignment method via multiple kernel learning

    NASA Astrophysics Data System (ADS)

    Sun, Bo; Zhang, Di; He, Jun; Yu, Lejun; Wu, Xuewen

    2015-10-01

    Face detection and alignment are two crucial tasks to face recognition which is a hot topic in the field of defense and security, whatever for the safety of social public, personal property as well as information and communication security. Common approaches toward the treatment of these tasks in recent years are often of three types: template matching-based, knowledge-based and machine learning-based, which are always separate-step, high computation cost or fragile robust. After deep analysis on a great deal of Chinese face images without hats, we propose a novel face detection and coarse alignment method, which is inspired by those three types of methods. It is multi-feature fusion with Simple Multiple Kernel Learning1 (Simple-MKL) algorithm. The proposed method is contrasted with competitive and related algorithms, and demonstrated to achieve promising results.

  9. DETECTION OF MULTIPLE BIPOLAR FLOWS IN NGC 7027 WITH SUBMILLIMETER ARRAY

    SciTech Connect

    Huang Zhenyuan; Hasegawa, Tatsuhiko I.; Dinh-V-Trung; Kwok, Sun; Muller, Sebastien; Hirano, Naomi; Lim, Jeremy; Muthu Mariappan, C.; Lyo, Aran E-mail: hirano@asiaa.sinica.edu.t E-mail: trung@asiaa.sinica.edu.t E-mail: jlim@asiaa.sinica.edu.t E-mail: muthu@aries.ernet.i

    2010-10-10

    Highly collimated multiple bipolar flows are detected with a 3'' resolution in the HCO{sup +} (J = 3-2) and HCN (J = 3-2) lines in the young planetary nebula NGC 7027 with the Submillimeter Array. The HCO{sup +} and HCN flows coincide in location and velocity with compact and fast CO flows detected with {approx}6'' resolutions with other millimeter arrays. The equatorial molecular torus of NGC 7027 is captured in HCO{sup +} emission in the present observations. The HCO{sup +} emission also closely follows the H{sub 2} emission, indicating that the present observations probe the photon-dominated region of the molecular envelope of NGC 7027.

  10. Signal processing for the detection of multiple imperfection echoes drowned in the structural noise.

    PubMed

    Drai, R; Benammar, A; Benchaala, A

    2004-04-01

    In this work, we propose to develop algorithms based on the split spectrum processing method associated with the multi-steps method based on "Group delay moving entropy" (GDME) allowing detecting and locating multiple imperfection echoes drowned in the structural noise of materials. In fact, GDME is based on the fact that defect echoes have a constant group delay while the noise has a random group delay. The investigation is performed with 4 known defect echoes with different characteristics (position, center frequency and bandwidth). The defect echo frequency is varied around the frequency of the input signal in order to evaluate, by signal to noise ratio calculation, the robustness of the detection method. The grain noise signal is generated first, by a simple clutter model which consider the noise, in the time domain, as the superimposed of signal coming from backscaterers in the medium and second, experimentally by a material with coarse grains. PMID:15047392

  11. Methods for radiation detection and characterization using a multiple detector probe

    DOEpatents

    Akers, Douglas William; Roybal, Lyle Gene

    2014-11-04

    Apparatuses, methods, and systems relating to radiological characterization of environments are disclosed. Multi-detector probes with a plurality of detectors in a common housing may be used to substantially concurrently detect a plurality of different radiation activities and types. Multiple multi-detector probes may be used in a down-hole environment to substantially concurrently detect radioactive activity and contents of a buried waste container. Software may process, analyze, and integrate the data from the different multi-detector probes and the different detector types therein to provide source location and integrated analysis as to the source types and activity in the measured environment. Further, the integrated data may be used to compensate for differential density effects and the effects of radiation shielding materials within the volume being measured.

  12. A Speech Endpoint Detection Algorithm Based on BP Neural Network and Multiple Features

    NASA Astrophysics Data System (ADS)

    Shi, Yong-Qiang; Li, Ru-Wei; Zhang, Shuang; Wang, Shuai; Yi, Xiao-Qun

    Focusing on a sharp decline in the performance of endpoint detection algorithm in a complicated noise environment, a new speech endpoint detection method based on BPNN (back propagation neural network) and multiple features is presented. Firstly, maximum of short-time autocorrelation function and spectrum variance of speech signals are extracted respectively. Secondly, these feature vectors as the input of BP neural network are trained and modeled and then the Genetic Algorithm is used to optimize the BP Neural Network. Finally, the signal's type is determined according to the output of Neural Network. The experiments show that the correct rate of this proposed algorithm is improved, because this method has better robustness and adaptability than algorithm based on maximum of short-time autocorrelation function or spectrum variance.

  13. Fluorescence enhancement and multiple protein detection in ZnO nanostructure microfluidic devices.

    PubMed

    Sang, Chen-Hsiang; Chou, Shu-Jen; Pan, F M; Sheu, Jeng-Tzong

    2016-01-15

    In this study, different morphological ZnO nanostructures, those of sharp nanowires (NWs), rod NWs, and hexahedral-puncheon nanostructures, were grown in microfluidic channels on the same glass substrate. Characterizations of correspondent biomolecule binding properties were simulated and demonstrated. The surface was modified using 3-ammineopropyl-triethoxysilane (3-APTES) and biotin-N-hydroxysuccinimide ester (NHS-biotin). Different concentrations (4.17pM to 41.7nM) of dye-conjugated streptavidin were simultaneously infused through the second microfluidic channels, which lie 90° from the first microfluidic channels. The florescent intensity at the crossover areas showed good agreement with simulations, with sharp ZnO NWs exhibiting the largest dynamic range and the highest fluorescent intensity. We further characterize correspondent protein detection using sharp ZnO NWs. The surfaces of these ZnO NWs were modified with mouse immunoglobulin G (IgG), infused through the second microfluidic channels with dye-conjugated (Alexa 546) anti-mouse IgG in different concentrations. Concentrations ranging from 417fM to 41.7nM can be resolved using sharp ZnO NWs. Finally, multiple protein detection was demonstrated using a five-by-eight microfluidic channel array. Fluorescence images present clear multiple detections at the crossover areas when using the sharp ZnO NWs for simultaneous dye-conjugated anti-mouse IgG and dye-conjugated anti-rabbit IgG (Alexa 647) detection. PMID:26322591

  14. Dual wavelength multiple-angle light scattering system for cryptosporidium detection

    NASA Astrophysics Data System (ADS)

    Buaprathoom, S.; Pedley, S.; Sweeney, S. J.

    2012-06-01

    A simple, dual wavelength, multiple-angle, light scattering system has been developed for detecting cryptosporidium suspended in water. Cryptosporidium is a coccidial protozoan parasite causing cryptosporidiosis; a diarrheal disease of varying severity. The parasite is transmitted by ingestion of contaminated water, particularly drinking-water, but also accidental ingestion of bathing-water, including swimming pools. It is therefore important to be able to detect these parasites quickly, so that remedial action can be taken to reduce the risk of infection. The proposed system combines multiple-angle scattering detection of a single and two wavelengths, to collect relative wavelength angle-resolved scattering phase functions from tested suspension, and multivariate data analysis techniques to obtain characterizing information of samples under investigation. The system was designed to be simple, portable and inexpensive. It employs two diode lasers (violet InGaN-based and red AlGaInP-based) as light sources and silicon photodiodes as detectors and optical components, all of which are readily available. The measured scattering patterns using the dual wavelength system showed that the relative wavelength angle-resolved scattering pattern of cryptosporidium oocysts was significantly different from other particles (e.g. polystyrene latex sphere, E.coli). The single wavelength set up was applied for cryptosporidium oocysts'size and relative refractive index measurement and differential measurement of the concentration of cryptosporidium oocysts suspended in water and mixed polystyrene latex sphere suspension. The measurement results showed good agreement with the control reference values. These results indicate that the proposed method could potentially be applied to online detection in a water quality control system.

  15. Multiple biomarkers biosensor with just-in-time functionalization: Application to prostate cancer detection.

    PubMed

    Parra-Cabrera, C; Samitier, J; Homs-Corbera, A

    2016-03-15

    We present a novel lab-on-a-chip (LOC) device for the simultaneous detection of multiple biomarkers using simple voltage measurements. The biosensor functionalization is performed in-situ, immediately before its use, facilitating reagents storage and massive devices fabrication. Sensitivity, limit of detection (LOD) and limit of quantification (LOQ) are tunable depending on the in-chip flown sample volumes. As a proof-of-concept, the system has been tested and adjusted to quantify two proteins found in blood that are susceptible to be used combined, as a screening tool, to diagnose prostate cancer (PCa): prostate-specific antigen (PSA) and spondin-2 (SPON2). This combination of biomarkers has been reported to be more specific for PCa diagnostics than the currently accepted but rather controversial PSA indicator. The range of detection for PSA and SPON2 could be adjusted to the clinically relevant range of 1 to 10 ng/ml. The system was tested for specificity to the evaluated biomarkers. This multiplex system can be modified and adapted to detect a larger quantity of biomarkers, or different ones, of relevance to other specific diseases. PMID:26590517

  16. Fully automatic detection of deep white matter T1 hypointense lesions in multiple sclerosis

    NASA Astrophysics Data System (ADS)

    Spies, Lothar; Tewes, Anja; Suppa, Per; Opfer, Roland; Buchert, Ralph; Winkler, Gerhard; Raji, Alaleh

    2013-12-01

    A novel method is presented for fully automatic detection of candidate white matter (WM) T1 hypointense lesions in three-dimensional high-resolution T1-weighted magnetic resonance (MR) images. By definition, T1 hypointense lesions have similar intensity as gray matter (GM) and thus appear darker than surrounding normal WM in T1-weighted images. The novel method uses a standard classification algorithm to partition T1-weighted images into GM, WM and cerebrospinal fluid (CSF). As a consequence, T1 hypointense lesions are assigned an increased GM probability by the standard classification algorithm. The GM component image of a patient is then tested voxel-by-voxel against GM component images of a normative database of healthy individuals. Clusters (≥0.1 ml) of significantly increased GM density within a predefined mask of deep WM are defined as lesions. The performance of the algorithm was assessed on voxel level by a simulation study. A maximum dice similarity coefficient of 60% was found for a typical T1 lesion pattern with contrasts ranging from WM to cortical GM, indicating substantial agreement between ground truth and automatic detection. Retrospective application to 10 patients with multiple sclerosis demonstrated that 93 out of 96 T1 hypointense lesions were detected. On average 3.6 false positive T1 hypointense lesions per patient were found. The novel method is promising to support the detection of hypointense lesions in T1-weighted images which warrants further evaluation in larger patient samples.

  17. Robust detection of multiple sclerosis lesions from intensity-normalized multi-channel MRI

    NASA Astrophysics Data System (ADS)

    Karpate, Yogesh; Commowick, Olivier; Barillot, Christian

    2015-03-01

    Multiple sclerosis (MS) is a disease with heterogeneous evolution among the patients. Quantitative analysis of longitudinal Magnetic Resonance Images (MRI) provides a spatial analysis of the brain tissues which may lead to the discovery of biomarkers of disease evolution. Better understanding of the disease will lead to a better discovery of pathogenic mechanisms, allowing for patient-adapted therapeutic strategies. To characterize MS lesions, we propose a novel paradigm to detect white matter lesions based on a statistical framework. It aims at studying the benefits of using multi-channel MRI to detect statistically significant differences between each individual MS patient and a database of control subjects. This framework consists in two components. First, intensity standardization is conducted to minimize the inter-subject intensity difference arising from variability of the acquisition process and different scanners. The intensity normalization maps parameters obtained using a robust Gaussian Mixture Model (GMM) estimation not affected by the presence of MS lesions. The second part studies the comparison of multi-channel MRI of MS patients with respect to an atlas built from the control subjects, thereby allowing us to look for differences in normal appearing white matter, in and around the lesions of each patient. Experimental results demonstrate that our technique accurately detects significant differences in lesions consequently improving the results of MS lesion detection.

  18. Simultaneous detection of multiple biomarkers by means of SERS on polymer nanopillar gold arrays

    NASA Astrophysics Data System (ADS)

    Morasso, Carlo; Picciolini, Silvia; Mehn, Dora; Pellacani, Paola; Frangolho, Ana; Marchesini, Gerardo; Vanna, Renzo; Gualerzi, Alice; Bedoni, Marzia; Marabelli, Franco; Gramatica, Furio

    2016-03-01

    The detection of biomarkers by means of Surface Enhanced Raman Spectroscopy (SERS) is foreseen to became a very important tool in the clinical practice because of its excellent sensitivity and potential for the simultaneous detection of multiple biomarkers. In the present paper we describe how it was possible to build a sensor for the detection of genetic biomarkers involved in acute myeloid leukemia. The assay is based on the use of a specifically designed SERS substrate made of a 2D crystal structure of polymeric pillars embedded in a gold layer. This substrate is characterized by good enhancing properties coupled with an excellent homogeneity. The SERS substrate was conjugated with DNA probes complementary to a target sequence and used in a sandwich assay with gold nanoparticles labeled with a second DNA probe and a Raman reporter. The so developed assay allowed the detection of a leukemia biomarker (WT1 gene) and an housekeeping gene with low picomolar sensitivity. At last, we optimized the assay in order to tackle one of the main limitations of SERS based assay: the loss of signal that is observed when the Raman spectra are collected in liquid. Combining a preferential functionalization on the polymeric pillars with a different height of the polymer pillars from the gold layer the assay demonstrated its effectiveness even when measured in buffer.

  19. Fully automatic detection of deep white matter T1 hypointense lesions in multiple sclerosis.

    PubMed

    Spies, Lothar; Tewes, Anja; Suppa, Per; Opfer, Roland; Buchert, Ralph; Winkler, Gerhard; Raji, Alaleh

    2013-12-01

    A novel method is presented for fully automatic detection of candidate white matter (WM) T1 hypointense lesions in three-dimensional high-resolution T1-weighted magnetic resonance (MR) images. By definition, T1 hypointense lesions have similar intensity as gray matter (GM) and thus appear darker than surrounding normal WM in T1-weighted images. The novel method uses a standard classification algorithm to partition T1-weighted images into GM, WM and cerebrospinal fluid (CSF). As a consequence, T1 hypointense lesions are assigned an increased GM probability by the standard classification algorithm. The GM component image of a patient is then tested voxel-by-voxel against GM component images of a normative database of healthy individuals. Clusters (≥0.1 ml) of significantly increased GM density within a predefined mask of deep WM are defined as lesions. The performance of the algorithm was assessed on voxel level by a simulation study. A maximum dice similarity coefficient of 60% was found for a typical T1 lesion pattern with contrasts ranging from WM to cortical GM, indicating substantial agreement between ground truth and automatic detection. Retrospective application to 10 patients with multiple sclerosis demonstrated that 93 out of 96 T1 hypointense lesions were detected. On average 3.6 false positive T1 hypointense lesions per patient were found. The novel method is promising to support the detection of hypointense lesions in T1-weighted images which warrants further evaluation in larger patient samples. PMID:24216694

  20. A fluorescence-based centrifugal microfluidic system for parallel detection of multiple allergens

    NASA Astrophysics Data System (ADS)

    Chen, Q. L.; Ho, H. P.; Cheung, K. L.; Kong, S. K.; Suen, Y. K.; Kwan, Y. W.; Li, W. J.; Wong, C. K.

    2010-02-01

    This paper reports a robust polymer based centrifugal microfluidic analysis system that can provide parallel detection of multiple allergens in vitro. Many commercial food products (milk, bean, pollen, etc.) may introduce allergy to people. A low-cost device for rapid detection of allergens is highly desirable. With this as the objective, we have studied the feasibility of using a rotating disk device incorporating centrifugal microfluidics for performing actuationfree and multi-analyte detection of different allergen species with minimum sample usage and fast response time. Degranulation in basophils or mast cells is an indicator to demonstrate allergic reaction. In this connection, we used acridine orange (AO) to demonstrate degranulation in KU812 human basophils. It was found that the AO was released from granules when cells were stimulated by ionomycin, thus signifying the release of histamine which accounts for allergy symptoms [1-2]. Within this rotating optical platform, major microfluidic components including sample reservoirs, reaction chambers, microchannel and flow-control compartments are integrated into a single bio-compatible polydimethylsiloxane (PDMS) substrate. The flow sequence and reaction time can be controlled precisely. Sequentially through varying the spinning speed, the disk may perform a variety of steps on sample loading, reaction and detection. Our work demonstrates the feasibility of using centrifugation as a possible immunoassay system in the future.

  1. Single and Multiple Change Point Detection in Spike Trains: Comparison of Different CUSUM Methods.

    PubMed

    Koepcke, Lena; Ashida, Go; Kretzberg, Jutta

    2016-01-01

    In a natural environment, sensory systems are faced with ever-changing stimuli that can occur, disappear or change their properties at any time. For the animal to react adequately the sensory systems must be able to detect changes in external stimuli based on its neuronal responses. Since the nervous system has no prior knowledge of the stimulus timing, changes in stimulus need to be inferred from the changes in neuronal activity, in particular increase or decrease of the spike rate, its variability, and shifted response latencies. From a mathematical point of view, this problem can be rephrased as detecting changes of statistical properties in a time series. In neuroscience, the CUSUM (cumulative sum) method has been applied to recorded neuronal responses for detecting a single stimulus change. Here, we investigate the applicability of the CUSUM approach for detecting single as well as multiple stimulus changes that induce increases or decreases in neuronal activity. Like the nervous system, our algorithm relies exclusively on previous neuronal population activities, without using knowledge about the timing or number of external stimulus changes. We apply our change point detection methods to experimental data obtained by multi-electrode recordings from turtle retinal ganglion cells, which react to changes in light stimulation with a range of typical neuronal activity patterns. We systematically examine how variations of mathematical assumptions (Poisson, Gaussian, and Gamma distributions) used for the algorithms may affect the detection of an unknown number of stimulus changes in our data and compare these CUSUM methods with the standard Rate Change method. Our results suggest which versions of the CUSUM algorithm could be useful for different types of specific data sets. PMID:27445714

  2. Linking landscape characteristics to local grizzly bear abundance using multiple detection methods in a hierarchical model

    USGS Publications Warehouse

    Graves, T.A.; Kendall, K.C.; Royle, J. Andrew; Stetz, J.B.; Macleod, A.C.

    2011-01-01

    Few studies link habitat to grizzly bear Ursus arctos abundance and these have not accounted for the variation in detection or spatial autocorrelation. We collected and genotyped bear hair in and around Glacier National Park in northwestern Montana during the summer of 2000. We developed a hierarchical Markov chain Monte Carlo model that extends the existing occupancy and count models by accounting for (1) spatially explicit variables that we hypothesized might influence abundance; (2) separate sub-models of detection probability for two distinct sampling methods (hair traps and rub trees) targeting different segments of the population; (3) covariates to explain variation in each sub-model of detection; (4) a conditional autoregressive term to account for spatial autocorrelation; (5) weights to identify most important variables. Road density and per cent mesic habitat best explained variation in female grizzly bear abundance; spatial autocorrelation was not supported. More female bears were predicted in places with lower road density and with more mesic habitat. Detection rates of females increased with rub tree sampling effort. Road density best explained variation in male grizzly bear abundance and spatial autocorrelation was supported. More male bears were predicted in areas of low road density. Detection rates of males increased with rub tree and hair trap sampling effort and decreased over the sampling period. We provide a new method to (1) incorporate multiple detection methods into hierarchical models of abundance; (2) determine whether spatial autocorrelation should be included in final models. Our results suggest that the influence of landscape variables is consistent between habitat selection and abundance in this system. ?? 2011 The Authors. Animal Conservation ?? 2011 The Zoological Society of London.

  3. Single and Multiple Change Point Detection in Spike Trains: Comparison of Different CUSUM Methods

    PubMed Central

    Koepcke, Lena; Ashida, Go; Kretzberg, Jutta

    2016-01-01

    In a natural environment, sensory systems are faced with ever-changing stimuli that can occur, disappear or change their properties at any time. For the animal to react adequately the sensory systems must be able to detect changes in external stimuli based on its neuronal responses. Since the nervous system has no prior knowledge of the stimulus timing, changes in stimulus need to be inferred from the changes in neuronal activity, in particular increase or decrease of the spike rate, its variability, and shifted response latencies. From a mathematical point of view, this problem can be rephrased as detecting changes of statistical properties in a time series. In neuroscience, the CUSUM (cumulative sum) method has been applied to recorded neuronal responses for detecting a single stimulus change. Here, we investigate the applicability of the CUSUM approach for detecting single as well as multiple stimulus changes that induce increases or decreases in neuronal activity. Like the nervous system, our algorithm relies exclusively on previous neuronal population activities, without using knowledge about the timing or number of external stimulus changes. We apply our change point detection methods to experimental data obtained by multi-electrode recordings from turtle retinal ganglion cells, which react to changes in light stimulation with a range of typical neuronal activity patterns. We systematically examine how variations of mathematical assumptions (Poisson, Gaussian, and Gamma distributions) used for the algorithms may affect the detection of an unknown number of stimulus changes in our data and compare these CUSUM methods with the standard Rate Change method. Our results suggest which versions of the CUSUM algorithm could be useful for different types of specific data sets. PMID:27445714

  4. Quantum dots targeted to vascular endothelial growth factor receptor 2 as a contrast agent for the detection of colorectal cancer

    NASA Astrophysics Data System (ADS)

    Carbary-Ganz, Jordan L.; Barton, Jennifer K.; Utzinger, Urs

    2014-08-01

    We successfully labeled colorectal cancer in vivo using quantum dots targeted to vascular endothelial growth factor receptor 2 (VEGFR2). Quantum dots with emission centered at 655 nm were bioconjugated to anti-VEGFR2 antibodies through streptavidin/biotin linking. The resulting QD655-VEGFR2 contrast agent was applied in vivo to the colon of azoxymethane (AOM) treated mice via lavage and allowed to incubate. The colons were then excised, cut longitudinally, opened to expose the lumen, and imaged en face using a fluorescence stereoscope. The QD655-VEGFR2 contrast agent produced a significant increase in contrast between diseased and undiseased tissues, allowing for fluorescence-based visualization of the diseased areas of the colon. Specificity was assessed by observing insignificant contrast increase when labeling colons of AOM-treated mice with quantum dots bioconjugated to isotype control antibodies, and by labeling the colons of saline-treated control mice. This contrast agent has a great potential for in vivo imaging of the colon through endoscopy.

  5. Detection of vascular endothelial growth factor (VEGF) and VEGF receptors Flt-1 and KDR in canine mastocytoma cells.

    PubMed

    Rebuzzi, Laura; Willmann, Michael; Sonneck, Karoline; Gleixner, Karoline V; Florian, Stefan; Kondo, Rudin; Mayerhofer, Matthias; Vales, Anja; Gruze, Alexander; Pickl, Winfried F; Thalhammer, Johann G; Valent, Peter

    2007-02-15

    Vascular endothelial growth factor (VEGF) is a major regulator of angiogenesis and a potential autocrine growth factor for neoplastic cells in various malignancies. In the present study, we have investigated expression of VEGF and VEGF receptors in canine mastocytomas and the canine mastocytoma cell line C2. As assessed by immunostaining of tissue sections and cytospin slides, primary neoplastic mast cells (MC) and C2 cells were found to express the VEGF protein. In Northern blot and RT-PCR experiments, C2 cells expressed VEGF mRNA in a constitutive manner. VEGF mRNA expression in C2 cells was counteracted by LY294002 and rapamycin, suggesting involvement of the PI3-kinase/mTOR pathway. Moreover, C2 cells were found to express VEGF receptor-1 (Flt-1) and VEGF receptor-2 (KDR). However, recombinant VEGF failed to promote (3)H-thymidine uptake in C2 cells, and a neutralizing anti-VEGF antibody (bevacizumab) failed to downregulate spontaneous proliferation in these cells. In addition, rapamycin decreased the expression of VEGF in C2 cells at the mRNA and protein level without suppressing their proliferation. Together, canine mastocytoma cells express VEGF as well as VEGF receptors. However, despite co-expression of VEGF and its receptors, VEGF is not utilized as an autocrine growth regulator by canine mastocytoma cells. PMID:17196258

  6. Parallel seed-based approach to multiple protein structure similarities detection

    DOE PAGESBeta

    Chapuis, Guillaume; Le Boudic-Jamin, Mathilde; Andonov, Rumen; Djidjev, Hristo; Lavenier, Dominique

    2015-01-01

    Finding similarities between protein structures is a crucial task in molecular biology. Most of the existing tools require proteins to be aligned in order-preserving way and only find single alignments even when multiple similar regions exist. We propose a new seed-based approach that discovers multiple pairs of similar regions. Its computational complexity is polynomial and it comes with a quality guarantee—the returned alignments have both root mean squared deviations (coordinate-based as well as internal-distances based) lower than a given threshold, if such exist. We do not require the alignments to be order preserving (i.e., we consider nonsequential alignments), which makesmore » our algorithm suitable for detecting similar domains when comparing multidomain proteins as well as to detect structural repetitions within a single protein. Because the search space for nonsequential alignments is much larger than for sequential ones, the computational burden is addressed by extensive use of parallel computing techniques: a coarse-grain level parallelism making use of available CPU cores for computation and a fine-grain level parallelism exploiting bit-level concurrency as well as vector instructions.« less

  7. Detection of multiple viral infections in cattle and buffalo with suspected vesicular disease in Brazil.

    PubMed

    Laguardia-Nascimento, Mateus; Sales, Érica Bravo; Gasparini, Marcela Ribeiro; de Souza, Natália Mendes; da Silva, Josiane Aparecida Gonçalina; Souza, Giovana Gonçalves; Carani, Fernanda Rezek; Dos Santos, Alyane Figueiredo; Rivetti Júnior, Anselmo Vasconcelos; Camargos, Marcelo Fernandes; Fonseca Júnior, Antônio Augusto

    2016-07-01

    Vesicular diseases are of high importance for livestock, primarily because of foot-and-mouth disease (FMD), which is a high-morbidity disease that generates direct losses caused by low milk production, weight loss, and indirect losses because of the need for sanitary barriers. Other vesicular diseases are also of importance for livestock because of direct impacts or because their clinical signs may be confused with those of FMD. We report herein the detection of multiple infections in cattle with suspected vesicular disease in the Brazilian states of Amazonas (AM), Mato Grosso (MT), and Roraima. Thirty-seven epithelial samples from cattle and 1 sample from a buffalo were sent to the laboratory for testing for FMDV and similar disease agents. All samples from MT were positive for parapoxvirus (Pseudocowpox virus and Bovine papular stomatitis virus). In addition, 3 samples were positive for Bluetongue virus, and 5 samples were positive for Bovine herpesvirus 1 Among these samples, 1 was positive for all of these 3 agents. Only 2 samples from AM were negative for parapoxvirus. The molecular tests conducted in this study detected multiple infections, with a high prevalence of parapoxvirus. PMID:27154321

  8. 3D cloud detection and tracking system for solar forecast using multiple sky imagers

    SciTech Connect

    Peng, Zhenzhou; Yu, Dantong; Huang, Dong; Heiser, John; Yoo, Shinjae; Kalb, Paul

    2015-06-23

    We propose a system for forecasting short-term solar irradiance based on multiple total sky imagers (TSIs). The system utilizes a novel method of identifying and tracking clouds in three-dimensional space and an innovative pipeline for forecasting surface solar irradiance based on the image features of clouds. First, we develop a supervised classifier to detect clouds at the pixel level and output cloud mask. In the next step, we design intelligent algorithms to estimate the block-wise base height and motion of each cloud layer based on images from multiple TSIs. Thus, this information is then applied to stitch images together into larger views, which are then used for solar forecasting. We examine the system’s ability to track clouds under various cloud conditions and investigate different irradiance forecast models at various sites. We confirm that this system can 1) robustly detect clouds and track layers, and 2) extract the significant global and local features for obtaining stable irradiance forecasts with short forecast horizons from the obtained images. Finally, we vet our forecasting system at the 32-megawatt Long Island Solar Farm (LISF). Compared with the persistent model, our system achieves at least a 26% improvement for all irradiance forecasts between one and fifteen minutes.

  9. 3D cloud detection and tracking system for solar forecast using multiple sky imagers

    DOE PAGESBeta

    Peng, Zhenzhou; Yu, Dantong; Huang, Dong; Heiser, John; Yoo, Shinjae; Kalb, Paul

    2015-06-23

    We propose a system for forecasting short-term solar irradiance based on multiple total sky imagers (TSIs). The system utilizes a novel method of identifying and tracking clouds in three-dimensional space and an innovative pipeline for forecasting surface solar irradiance based on the image features of clouds. First, we develop a supervised classifier to detect clouds at the pixel level and output cloud mask. In the next step, we design intelligent algorithms to estimate the block-wise base height and motion of each cloud layer based on images from multiple TSIs. Thus, this information is then applied to stitch images together intomore » larger views, which are then used for solar forecasting. We examine the system’s ability to track clouds under various cloud conditions and investigate different irradiance forecast models at various sites. We confirm that this system can 1) robustly detect clouds and track layers, and 2) extract the significant global and local features for obtaining stable irradiance forecasts with short forecast horizons from the obtained images. Finally, we vet our forecasting system at the 32-megawatt Long Island Solar Farm (LISF). Compared with the persistent model, our system achieves at least a 26% improvement for all irradiance forecasts between one and fifteen minutes.« less

  10. Parallel seed-based approach to multiple protein structure similarities detection

    SciTech Connect

    Chapuis, Guillaume; Lavenier, Dominique

    2015-01-01

    Finding similarities between protein structures is a crucial task in molecular biology. Most of the existing tools require proteins to be aligned in order-preserving way and only find single alignments even when multiple similar regions exist. We propose a new seed-based approach that discovers multiple pairs of similar regions. Its computational complexity is polynomial and it comes with a quality guarantee—the returned alignments have both root mean squared deviations (coordinate-based as well as internal-distances based) lower than a given threshold, if such exist. We do not require the alignments to be order preserving (i.e., we consider nonsequential alignments), which makes our algorithm suitable for detecting similar domains when comparing multidomain proteins as well as to detect structural repetitions within a single protein. Because the search space for nonsequential alignments is much larger than for sequential ones, the computational burden is addressed by extensive use of parallel computing techniques: a coarse-grain level parallelism making use of available CPU cores for computation and a fine-grain level parallelism exploiting bit-level concurrency as well as vector instructions.